Improve some translatable strings
Updated Norwegian bokmål translation
Use single-quotes for untranslatable strings
Make pep8 and pyflakes happy
Make pep8 and pyflakes happy
Set correct valign for now playing symbol on artists view

Fixes #142
Updated Czech translation
During travis check build gnome-music on Saucy via makecheck
Updated Brazilian Portuguese translation proofread by Enrico Nicoletto
Merge pull request #152 from roignac/quotes

Use single-quotes for untranslatable strings
Set correct valign for now playing symbol on artists view

Fixes #142
Merge pull request #163 from roignac/advanced_travis

During travis check build gnome-music on Saucy via makecheck
Merge pull request #153 from roignac/nowplaying_artists

Set correct valign for now playing symbol on artists view
Do model.append() in idle_add to speed up element adding
Use crossfade transition when switching artists
Re-work adding tracks on artists view
Merge pull request #160 from gnome-prototypes-team/add_item_speedup

Add item speedup
Use rtl variants of icons when using RTL languages
Fix a regression that causes a segfault in GTK+ 3.8
Merge pull request #168 from kyoushuu/segfault-regression

Fix a regression that causes a segfault in GTK+ 3.8