Thanks for the hint, Juanito!
I pm'ed the creator of the extension, but don't have much hope, since he was last active in Sept 2012 (as per his profile).
I've now installed libnl1 from the 4.x version and I'm stuck now, hence, I would like to ask for more advice.
The adapter I've got is a Sitecom WIFI N300 USB  Adapter, Product code WLA-2103 V1 001, with vendor/product id 0df6:0070 (as seen by lsusb). I haven't found much of the 2103, more of the 2102. I have to assume so far, that the chipset (rtl8192cu) is the same. 
And here the problems are starting. I've loaded the following TCLs:
usb-utils.tcz
wireless-3.8.13-tinycore.tcz
wireless_tools.tcz
hostapd.tcz
firmware.tcz
firmware-rtlwifi.tcz
wl-r8192cu-3.8.13-tinycore.tcz
As mentioned before, hostapd.tcz is from the 4.x repo, as well as the libnl1.tcz, which hostapd depends on (I amended the *.dep file).
I assume, that the load order does not matter, but I have the suspicion, that I'm double and triple loading stuff and that the odd TCZ might not be required. I'm totally confused after tons of testing and failures and I'm still not there.
Also, I blacklisted rtl8192cu (as per info file).
After a fresh re-boot, iwconfig reports wlan0 nicely, ifconfig as well (ifconfig wlan0 up). So far the starting point.
In hostapd.conf, I set the driver to
driver=rtl8192cu
Starting hostapd gives me
Configuration file: /home/tc/hostapd.conf
Line 19: invalid/unknown driver 'rtl8192cu'
1 errors found in configuration file '/home/tc/hostapd.conf'
Now, having seen that, I checked with lsmod: 
Module                  Size  Used by    Tainted: G  
ipt_MASQUERADE         12288  1 
iptable_nat            12288  1 
nf_conntrack_ipv4      16384  1 
nf_defrag_ipv4         12288  1 nf_conntrack_ipv4
nf_nat_ipv4            12288  1 iptable_nat
nf_nat                 16384  3 ipt_MASQUERADE,iptable_nat,nf_nat_ipv4
nf_conntrack           40960  5 ipt_MASQUERADE,iptable_nat,nf_conntrack_ipv4,nf_nat_ipv4,nf_nat
rtlwifi                73728  0 
rtl8192c_common        45056  0 
mac80211              155648  2 rtlwifi,rtl8192c_common
cfg80211              110592  2 rtlwifi,mac80211
mperf                  12288  0 
cpufreq_stats          12288  0 
cpufreq_powersave      12288  0 
cpufreq_conservative    12288  0 
cpufreq_userspace      12288  0 
8192cu                499712  0 
squashfs               24576 66 
loop                   20480 132 
ppdev                  12288  0 
parport_pc             24576  0 
parport                24576  2 ppdev,parport_pc
battery                16384  0 
e1000                  77824  0 
ac                     12288  0 
microcode              12288  0 
pcspkr                 12288  0 
8192cu, rather than rtl8192cu.  

USB-Devices reports the correct driver for the stick:
T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0df6 ProdID=0070 Rev=02.00
S:  Manufacturer=Realtek
S:  Product=802.11n WLAN Adapter
S:  SerialNumber=00e04c000001
C:  #Ifs= 1 Cfg#= 1 Atr=a0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 4 Cls=ff(vend.) Sub=ff Prot=ff Driver=rtl8192cu
driver=nl80211
ends in:
Configuration file: /home/tc/hostapd.conf
nl80211 driver initialization failed.
driver=mac80211 behaves like driver=rtl8192cu (invalid/unknown driver)
I've been loading the TCZs in all sorts of combinations, but no success.
Having been confused about what lsmod reports (8192cu, rather than rtl8192cu), I also blacklisted 8192cu and went throught the above tests again.
lsmod reports:
Module                  Size  Used by    Not tainted
ipt_MASQUERADE         12288  1 
iptable_nat            12288  1 
nf_conntrack_ipv4      16384  1 
nf_defrag_ipv4         12288  1 nf_conntrack_ipv4
nf_nat_ipv4            12288  1 iptable_nat
nf_nat                 16384  3 ipt_MASQUERADE,iptable_nat,nf_nat_ipv4
nf_conntrack           40960  5 ipt_MASQUERADE,iptable_nat,nf_conntrack_ipv4,nf_nat_ipv4,nf_nat
rtl8192cu              69632  0 
rtlwifi                73728  1 rtl8192cu
rtl8192c_common        45056  1 rtl8192cu
mac80211              155648  3 rtl8192cu,rtlwifi,rtl8192c_common
cfg80211              110592  2 rtlwifi,mac80211
mperf                  12288  0 
cpufreq_stats          12288  0 
cpufreq_powersave      12288  0 
cpufreq_userspace      12288  0 
cpufreq_conservative    12288  0 
squashfs               24576 66 
loop                   20480 132 
ppdev                  12288  0 
parport_pc             24576  0 
microcode              12288  0 
parport                24576  2 ppdev,parport_pc
ac                     12288  0 
battery                16384  0 
e1000                  77824  0 
pcspkr                 12288  0 
8192cu has disappeared and rtl8192cu shows up.
Unfortunately, now iwconfig does not list wlan0 anymore and, hence, everything else fails from here.
Long story short, I don't know, what else to try. Is the problem located between my ears or is there anything missing or wrong? I know, I'm playing with 4.x stuff and there is a fair chance the problem lies there, but may be there is something else wrong with it???
Your help is very much appreciated!
Regards
Carsten