Color/brightness tweaks for a variety of monster tiles.

Gargoyles, tengu, demonspawn outfits, and some others.
Document some template functions.
Don't shadow a method with a parameter.
Remove swapv in favour of std::swap
Move rather than copy in erase_any.

By moving rather than copying the last element into its new place.
Use make_pair when possible, emplace_back occasionally.
Use more emplacement and initializer lists.

And change a few function return types and vector value types
from string to const char *, to reduce copying.
remove CMD_MOVE_NOWHERE, since it is identical to CMD_WAIT
Update renamed commands in keybind.txt
Update the description of CMD_ATTACK_*, too.