Check if librt exists independent of OS, to be able to exclude librt on Android builds, even though it is a 'Linux'.
Improve documentation for merging
Merge pull request #2130 from worblehat/development

Check if librt exists independent of OS, to be able to exclude librt on ...
Add option to limit blame to first parent
Add unit test
Merge pull request #2132 from ethomson/merge_doc

Improve documentation for merging
Staticize file-local variables
Avoid casting warning
Prevent icc warning
Document enumerator and rewording
Use a portable cast
Merge pull request #2134 from libgit2/ben/icc

Fix Intel compiler warnings
Move system directory cache out of utils
Include stdarg.h for the va_copy test
Remove now-duplicated stdarg.h include
Merge pull request #2139 from ethomson/va_copy_warning

Include stdarg.h for the va_copy test
Merge pull request #2138 from ethomson/sysdir

Move system directory cache out of utils
Reset num_parents to 1 only for merge commits

Also, correct test case to account for the boundary flag
Remove "ignore" state from the git.git-authors
Merge pull request #2142 from ethomson/ignore_authors

Remove "ignore" state from the git.git-authors