Corrected a typo in Tessellator#addQuadraticVertex()

Fixes #2648 - corrected a typo in a5cbb0e2
Fixed error reporting for bez/quad/curve vertices

When user calls bezierVertex()/quadraticVertex()/curveVertex() and does
not call beginShape()/beginShape(POLYGON) before or forgets to specify
first vertex(), proper error message is shown.
Use correct collection in Library.list
Add missing translations for OS X menu
Merge pull request #2726 from federicobond/missing-translations

Add missing translations for OS X menu
Merge pull request #2721 from federicobond/library-bugfix

Use correct collection in Library.list
Add language hooks for UpdateCheck and ColorChooser
Merge pull request #2728 from federicobond/improve-localization

Add language hooks for UpdateCheck and ColorChooser
Merge pull request #2649 from JakubValtar/shape-fix

Corrected a typo in Tessellator#addQuadraticVertex()