First pass at patching (probably integer files only)
Use argv[0] to get the command name for the usage info.
More helpful messages should patching fail.
Add append_hunk function to the api.
Move variable definitions nearer to their point of use.
Add patch_frames to .gitignore
Merge branch 'patch_tool'

Note: Does not currently work on float-based wav data!

Conflicts:
	include/adiff.h
	include/diff_types.h
	src/hunk.h