Merge pull request #31 from ccaccb/gitignore

add compare-image binary to .gitignore
Destroy (most) of the libav data structures created during file loading and
saving.

This ensures that we close the context and streams that are created from
libav; this might still not be complete, but there seems to be different
APIs between libav and ffmpeg so I'm changing one piece at a time.

Works towards closing Issue #26.
correct multiindex handling
before this unpaper would silently fail on errors in parsing multiindexes.
Now we throw error messages and quit processing.
Also added tests for multiindexes.
correct unintended change
fix a possible printf(NULL) when -debug is used
Merge pull request #34 from ccaccb/fix_segfault

fix a possible printf(NULL) when -debug is used
Better error checks in argument parsing.
Also created two methods (one for float, one for int) which parse a single int/float.
These methods also get a string of the option for which the argument is parset.
This allows to display an error like "failed parsing of 'wrong' for option --option" to be displayed.
merge of branch multiindex
Merge branch 'better_parsing' into ffmpeg
Add option string to multiindex parsing to allow for detailed error output.
Also throw error on unexpected multiindex delimiter.
Add error checks in parseInts/Floats function.
Also add '' around the options to make it clearer to the user
that e.g. -w triggers on only one dash.
mend
Merge branch 'multiindex' into ffmpeg
Merge branch 'better_parsing' into ffmpeg