It turns out that commit 31e9cfc4cbcaf1b38cdd3dbe3282a8f57e5366a5
did not fix the GIT_USUSED behavior on all platforms. This commit
walks through and really cleans things up more thoroughly, getting
rid of the unnecessary stuff.
To remove the use of some GIT_UNUSED, I ended up adding a couple
of new iterators for hashtables that allow you to iterator just
over keys or just over values.
In making this change, I found a bug in the clar tests (where we
were doing *count++ but meant to do (*count)++ to increment the
value). I fixed that but then found the test failing because it
was not really using an empty repo. So, I took some of the code
that I wrote for iterator testing and moved it to clar_helpers.c,
then made use of that to make it easier to open fixtures on a
per test basis even within a single test file.
* Implemented git_diff_index_to_tree
* Reworked git_diff_options structure to handle more options
* Made most of the options in git_diff_options actually work
* Reorganized code a bit to remove some redundancy
* Added option parsing to examples/diff.c to test most options
This fixes several bugs, updates tests and docs, eliminates the
FILE* assumption in favor of printing callbacks for the diff patch
formatter helpers, and adds a "diff" example function that can
perform a diff from the command line.
