Assets 3

NEW release: 2c8cfa4
OLD release: b8703f7

Features:
#233 Mashup template: extract css to scss and make responsive by default
#232 Default template: extract css to scss and make responsive by default
#231 White template: extract css to scss and make responsive by default

Enhancements:
#235 Return 404 error when directly accessing storage folder
#230 Messy template: extract css to scss

Fix:
#234 Remove XML invalid characters from user input