Add method is_shallow to determine if the repository was a shallow clone
Change repository method to S4 method
Change init method to S4 method
Rename argument object to repo in tags method
Change clone method to S4 method
Change error to Rf_error in git2r C code

* src/*.c: Change the call to the error function to Rf_error so it's
  clear in the code that is the R error function that is called.
More specific check of git2r_arg_check_* return value

* src/*.c: Signal error if the return value from git2r_arg_check_* !=
  0.
Improve error messages from argument checking
Change return value on error to -1 in git2r_arg_check_* functions

* src/git2r_arg.c: Changed return value on error to -1 from 1 to be
  consistent with negative return values on error in libgit2.
Get configured upstream canonical name from local branch

* src/git2r_branch.c/h (git2r_branch_upstream_canonical_branch): Get
  the configured canonical name of the upstream branch, given a local
  branch, i.e "branch.branch_name.merge" property of the config file.

* src/git2r.c: Add git2r_branch_upstream_canonical_branch to callMethods
Get canonical name from branch

* src/git2r_branch.c/h (git2r_branch_canonical_name): Get the full
  name of a branch.

* src/git2r.c: Add git2r_branch_canonical_name to callMethods
Fix push of S4 class git_branch
Add push branch example
Parsimony in valgrind Rule

The proposed rule should be equivalent to the previous lines but will allow you to add new tests to the /tests directory without changing the makefile. WARNING I was unable to test this code as I do not have the valgrind debugger.
Merge pull request #46 from trosendal/patch-2

Parsimony in valgrind rule
Fix memory leak when listing parents of a commit

* src/git2r_commit.c (git2r_commit_parent_list): Add missing free of
  allocated git_commit objects.
Fix memory leak when running diff

* src/git2r_diff.c (git2r_diff_tree_to_wd, git2r_diff_tree_to_index,
  git2r_diff_tree_to_tree): Free allocated git_diff objects.
Fix to have consistent code style

* Change 'if(' to 'if ('
Updated libgit2 source code (59e3f45)

* Updated libgit2 source code to commit
  59e3f45b6150984e6a74ce79062caa459eda369f

* src/libgit2 (util.c, cache.c): Changed printf to Rprintf
Fix to build with updated libgit2

* src/git2r_remotes.c (git2r_remote_rename): Fix to handle changed libgit2 API