Major code refactoring

* Major code restructuring in preparation for new Invenio
  code structure.
Changed license from GPLv2 to GPLv3
installation: update gitignore
docs: Sphinx Makefile
Merge branch 'master' into next

Conflicts:
	bibfield/Makefile.am
	bibfield/etc/Makefile.am
	configure.ac
installation: change default site-configuration

* Changes default site configuration to be loaded via
  entry points.
base: fix views and travis file
jsonext: migrate bibfield to jsonalchemy
restapi: move to invenio
tests: migrate datacite xml validation
global: pu-branch migration mega commit
base: removal of font awesome

* Moves Font Awesome to Invenio and installation via
  bower.json.
deposit: upgrade of font-awesome to version 4

* Upgrades deposit icons to Font Awesome v4.
deposit: template and bootstrap 3 fixes

* Fixes some template issues as well as bootstrap 3 issues.
global: travis and requirements updates.
github: initial release
installation: packaging and configuration fix
base: header and css fix
legacy: tasklets pu-branch fixes

* Fixes migration issues to pu-branch.
deposit: pu-branch migration fixes