Basic global search
Merge branch 'search' of https://github.com/xyzz/weblate into search

Conflicts:
	trans/forms.py
	trans/views/basic.py
Simplify search query generating
Remove hardcoded limitation from search
Document function
A bit of coding style
Paginate search results
Show search form on results page
Display project info on search page
Show status flag in search results
Merge branch 'search'

Closes #317
Document changes
Add test case for searching

Issue #317