URL and typo
code alignment, typos, better comment

* code alignment: vendor prefix properties are right-aligned
* .pln and .pl0 (for example) both exist and are equivalent. Comment should reflect that
* no space before a ':' (in the flex part)
* s/haslayout/hasLayout
Merge pull request #1 from PhilippeVay/master

Test (from github.com graphical interface)