code cleaning
reworked iid slightly
code cleaning
slight changes to hash cutoff types stored in search
fixed backwards cutoff types
code cleaning
Revert "code cleaning"

This reverts commit aab9926f54caafcce4cf7a408a63ccbe11b8a0a5.

no need to check something for iid, depth will eventually go
to zero and cause qsearch start
added skip null move check back to stack
converted fully back to stack based search
added means of returning chosen move from stack
code cleaning
much cleaner iid implementation
code cleaning
code cleaning
much cleaner verification search implementation
code cleaning
fix bad killer store in null move stage
code cleaning
merged stack based search to master
code cleaning