Remote revamp (director's cut)

A previous commit forgot to update the head list after push as well,
leading to wrong output of git_remote_ls().

These tests were forgotten when modifying git_remote_ls().

Copy the pointers into temporary vectors instead of assigning them tot
he same array so we don't mess up with someone else's memory by
accident (e.g. by sorting).

The callback-based method of listing remote references dates back to the
beginning of the network code's lifetime, when we didn't know any
better.

We need to keep the list around for update_tips() after disconnect() so
let's make use of this to simply give the user a pointer to the array so
they can write straightforward code instead of having to go through a
callback.

Removing arbitrary refspecs makes things more complex to reason
about. Instead, let the user set the fetch and push refspec list to
whatever they want it to be.

Fix warning in tests-clar/merge/workdir/trivial.c

Correctly quote config values while saving

Streamline url-parsing logic.

update example to new packfile creation signature

Allow callers to set mode on packfile creation

Add git_packbuilder_hash to query pack filename

Signed-off-by: Sven Strickroth <email@cs-ware.de>

Signed-off-by: Sven Strickroth <email@cs-ware.de>

Signed-off-by: Sven Strickroth <email@cs-ware.de>

If the value contains a command (; or #) char or starts or ends with space it needs to be quoted.

Signed-off-by: Sven Strickroth <email@cs-ware.de>

don't double free pkt

Change the git_branch_iterator_new definition to use git_branch_t

Plug configuration file search paths tests leaks

Plug git_merge() related leaks

merge!

Fix leaks

branch: move from foreach to an iterator