First try to replace all application and apps with project

Still TODO:
Replace application/apps in translations and there refs!
Review application and app in test python files!
point to new associated theme for renaming
change app to project in descriptions and strings for test_admin.py
replace 'Manage featured applications'
add missing translation points
use merged new theme
rename 'Create an App'
updated pybossa js and pybossa theme
point to new theme
app to project change for test
use sampleapp for now
test app rename
rename test default
uppercase character
merge master and fix merge conflicts
remove bad renaming
resolve indention merge error
point to new pybossa.js inside pybossa theme
Update translation files

See instructions in #806
TODO is still a edit and review of .po translations. See #807
Merge branch 'issue-531-rename-apps-v2' of https://github.com/PyBossa/pybossa into issue-531-rename-apps-v2