Merge pull request #1286 from CautiousAlbino/master

Log when context driver fails to bind API.
Add sha1_calculate (takes a filename path)
Move SHA1 text to proper place
Add Categories and System info to 'Core Information'
Core Information - add Core Name / System Manufacturer
Remove unused/stub 'Cheat Settings' setting
We're not going to use 'cheat database' from bsnes XML cheats,
but for our more general-purpose cheats in cores
Runloop - early return if g_extern.cheat is NULL
Fix nasty breakage when joypad index >= MAX_PLAYERS.

No bounds checking and joypad index is apparently now unsigned so old
"disabled" values in config will now overflow instead ...