Fix build break from previous commit ‒ not necessary anyway

GCC chokes on SL(__PRETTY_FUNCTION__), claiming it expands to
u8__PRETTY_FUNCTION__. This is inconsistent with the successful expansion
of SL(__FILE__), but since it’s not really/ necessary, we just avoid
using SL() here.
Merge remote-tracking branch 'origin/vs2010'
Fix documentation
Add “message” 2nd arg to ABC_ASSERT, like in Python’s assert
Add missing 2nd arg to ABC_ASSERT