[enh] Show real user photo
[enh] Add links to footer and show last activity for courses
[ref] Refactoring home view.

Now following a Category == Following all Courses in this category
[add] Softer clean rul for Makefile + add debug log files
[add] Node canonic URL
[add] Logo in #navbar #brand
[fix] make reset should cleandata
[enh] Documents reference their original version
[enh] Download documents + update views and downloads counters
[enh] Show document description when hovering its name
[enh] Access category page from navbar
[fix] Encoding issues
[fix] PreNotification is spawned by signal
[fix] A message should reference the previous
[enh] fix #17: render $expression$ as TeX Math in threads
[fix] Don't use too long code lines =)
[fix] Only dest user should be able to read its notifications
[fix] PDF viewer design glitch
[fix] If no url given when auth come back, goto home
[fix] Navabar categories title in bold