This converts virtually all of the places that allocate GIT_PATH_MAX
buffers on the stack for manipulating paths to use git_buf objects
instead. The patch is pretty careful not to touch the public API
for libgit2, so there are a few places that still use GIT_PATH_MAX.
This extends and changes some details of the git_buf implementation
to add a couple of extra functions and to make error handling easier.
This includes serious alterations to all the path.c functions, and
several of the fileops.c ones, too. Also, there are a number of new
functions that parallel existing ones except that use a git_buf
instead of a stack-based buffer (such as git_config_find_global_r
that exists alongsize git_config_find_global).
This also modifies the win32 version of p_realpath to allocate whatever
buffer size is needed to accommodate the realpath instead of hardcoding
a GIT_PATH_MAX limit, but that change needs to be tested still.
1. The license header is technically not valid if it doesn't have a
copyright signature.
2. The COPYING file has been updated with the different licenses used in
the project.
3. The full GPLv2 header in each file annoys me.
Cleaned up the structure of the whole OS-abstraction layer.
fileops.c now contains a set of utility methods for file management used
by the library. These are abstractions on top of the original POSIX
calls.
There's a new file called `posix.c` that contains
emulations/reimplementations of all the POSIX calls the library uses.
These are prefixed with `p_`. There's a specific posix file for each
platform (win32 and unix).
All the path-related methods have been moved from `utils.c` to `path.c`
and have their own prefix.
