added extra/enlightenment

Vanilla version from ABS
extra/enlightenment: fix segfault on start

enlightenment_start stops very quickly with a segfault:
(gdb) bt
 #0  0xb6bcba1c in pause () from /usr/lib/libpthread.so.0
 #1  <signal handler called>
 #2  0x0007672c in e_desk_show ()
 #3  0x0010ace8 in e_zone_desk_count_set ()
 #4  0x00000000 in ?? ()

After recompiling with debug symbols, I noticed this is due to
some memory corruption, and found an upstream patch that fixes the
problem (applied in their enlightenment-0.18 branch but not in
release 0.18.8):
http://git.enlightenment.org/core/enlightenment.git/commit/?h=enlightenment-0.18&id=590eb392f1438d2cde775a93aa1178c61b75e9e7

Technically, the bug is also present on x86, but does not cause a
segfault.
Merge pull request #899 from drinkcat/e17-patch-overflow

extra/enlightenment: Add package and add patch to fix segfault