Work around strict aliasing in array growth

This works around strict aliasing rules letting some versions of
GCC (particularly on RHEL 6) thinking that they can skip updating the
size of the array when calculating the next element's offset.

Preallocating two commits doesn't make much sense as leaving allocation
to the first array usage will allocate a sensible size with room for
growth.

This preallocation has also been hiding issues with strict aliasing in
the tests, as we have fairly simple histories and never trigger the
growth.

Don't allow conflicts by default

Fix git status list new unreadable folder

Rename git_cherry_pick to git_cherrypick

Export git_buf_text_is_binary and git_buf_text_contains_nul.

When adding new config section, handle config file not ending with LF

Handle local file:/// paths on Windows

So that users don’t need to implement binary detection themselves.

Update perl bindings link

Switch description and message reporting in `clar__assert_equal_file`

Windows can't handle a path like `/c:/foo`; when turning file:///
URIs into local paths, we must strip the leading slash.

Windows compatibility fixes 

ssh: provide a factory function for setting ssh paths

Support refspecs with the asterisk in the middle

Properly report failure when expanding a packfile

merge: don't open COMMIT_MSG unless we need to append conflicts

Fixup git_attr_value's comment to be recognised as documentation, and
include the definitions needed for clang to parse reset.h such that
it shows up in the documentation.

This fixes #2430.

git allows you to set which paths to use for the git server programs
when connecting over ssh; and we want to provide something similar.

We do this by providing a factory function which can be set as the
remote's transport callback which will set the given paths upon
creation.