Fixed #71 and #72. Some small simplifications.

Fixed the way timetracker notes are fetched on init (in the 0.9.2 version it was creating an unnecessary branch for them)

• Improved error messages; they don't output the whole help now
• Improved init command; no need for manual notes branch update
• Fixed close task:
  • using 'gtm push'
  • first push task branch, then try to merge
  • better merge failure message

Now pre-commit hook doesn't fail commit (only warns) if you forgot to set the timer.
After updating run gtm init to rewrite the hook.

• Added a command alias for gtm connect: gtm issue-to-pull-request
• Fixed #65 : connect the task on first gtm push

• #67: gtm tree show somewhat like a tree of branches with respect to their base branches
• gtm info shows now what is the base branch too

Fixed behavior of gtm note:

• without args it opens editor
• if the first arg doesn't start from dash, it is treated as a message
• it can take any other arguments for git commit

#58: Added some shortcuts:

• + <time> instead of +<time>; same for -; the +/- operation as shortcut for set
• gtm push --tag or smth like this for gtm push && git push --tag;
• gtm note "message" for git commit --alow-empty -m "message";

#59: Added log info with confirmation in gtm undo

#64: Added automatic deletion of remote branch (which is already archived) in gtm close.