fix windows build and m_spec overflow
Merge pull request #320 from default-kramer/biquad_fixes

fix windows build and m_spec overflow
In preparation of the #316 merge, add LV2 icon to the available preferences icons & update icon template with LV2 layer.
Merge branch 'master' of git://github.com/mixxxdj/mixxx into variables_svg
prettyprint + code dup removal
80 char per line max