Don't prefix output from jgit status with '# '

C Git does not do it anymore

Bug: 439937
Change-Id: I20bdb787a00bba3e4adf269fd64ec6296bdc2a66
Update SUBMITTING_PATCHES

It contained outdated information about attaching patches to bug
reports. Shorten it to the essentials.

Also format it using markdown and rename it to CONTRIBUTING.md, which is
a convention and doesn't include "patches" in the name.

Change-Id: I9ee73f16e6fa8fbf529ac0ca791e2375d4d56d68
Signed-off-by: Robin Stocker <robin@nibor.org>
Handle initial checkout correctly

As described in native gits file "git-read-tree.txt" git has in a
special mode when doing the "initial" checkout. "Initial" means that the
index is empty before the checkout. This was not handled correctly in
JGit and is fixed in this commit. Also see
https://github.com/git/git/blob/master/Documentation/git-read-tree.txt#L181

Change-Id: I9b9d1bd9ebf349cfca420c891c7b099a18d07ba4