Revert "Use git_helpers to get version number"

This reverts commit 3754de6ae6e81060748297ad9e46e6a9169402bc.

Reverting the above commit fixes freezing on loading.

See ticket #157.
Fix gtk threads initialization

GUI was freezing when using a MicroDrop plugin that used pop-up dialogs.
This commit, seems to fix the problem.  Note that any code that *might* be
called from another thread *(e.g., a `idle_add` callback)* must be wrapped as
follows:

    gtk.gdk.threads_enter()
    ... code ...
    gtk.gdk.threads_leave()

See [here][1] and [here][2].

[1]: http://stackoverflow.com/questions/7850134/pygtk-thread-not-running-until-main-quits
[2]: http://faq.pygtk.org/index.py?req=edit&file=faq20.006.htp
Add `v1` prefix to default updates URL

Add `v1` prefix to default updates URL.

Applying a version prefix to the updates URL path
makes is possible to maintain a separate update
repository for each major MicroDrop version.
Explicitly require pyutilib==3.9.2706

Explicitly require `pyutilib==3.9.2706`, since version 4.0 deprecates
the
`PluginGlobals.push_env` method and replaces it
with `PluginGlobals.add_env` method.

Updating the `microdrop` source to use `add_env` should likely make
things work with the latest `pyutilib`.
Merge remote-tracking branch 'github/dev' into dev