Software Público Brasileiro

This commit introduces a lot of changes in the HTML generated by Nosfero
with the intent of making it load faster on users' browsers. This
includes:

  * Adding apache configuration for compression of text content and
    aggresive cache policy (caching assets for 1 month)
  * Drastically reducing the number of stylesheets and javascript files
    referenced in the HTML.
  * The remaining CSS and Javascript files are now cached in a single file
    (one CSS file and one Javascript file) so that clients will only
    request a single file instead of several ones (and thus requiring a
    single HTTP connection instead of several ones).
  * Making sure that all assets referenced in the code have a timestamp
    (?21083219837) in the end of the URL so that when they are updated the
    client will fetch them again.

During the course of the implemeantion, some other changes were made:

  * Updated INSTALL file with documentation about apache configuration for
    production environments.
  * Marked as deprecated all methods that use stylesheet_import, as well
    as stylesheet_import itself.
  * Removed "better browser promotion" code. It sucks.
  * Unifyed Noosfero stylesheets)
  * Unifyed stylesheets in the base theme
  * Enhanced the sample-data script with the creation of random events.
    in a range of 60 days around the current date, so that there will be
    events in the previous month, in the current month and in the next
    month.
  * Removed unused cms.js
  * Updated .gitignore example to ignore cached CSS and Javascript files.
  * Updated git-upgrade script to remove cached CSS and Javascript files.

(ActionItem1425)