Bugfix: Check if maf and mac respectively exist

When uploading GWAS plots, sometimes there are no macs and mafs information. In
 order to avoid a NullPointerException the MetaAnalysisService checks if those fields
  exists in  the fulltext search response.
Feature: New widget for displaying progressbar as  a circle

This CircularProgressBar widget allows to show progress in circular form.
It is based on http://blog.invatechs.com/round_progress_bar_with_html5_css3_and_javascript.
Feature: Display of GWAS status was enhanced.

* Instead of displaying the GWAS status below the analysis details, it is displayed next to it.
* Instead of a horizontal ProgressBar a circular ProgressBar (CircularProgressBar.java) is
 used
 * The action dropdown button (Run on HPC) and the status label (N/A, Finished) are
  collapsed into one  DropDownButton. Furthermore additional actions are enabled:
    - Status = 'Error' -> Delete/Re-run
    - Status = 'Finished' -> Delete