Resolved ambiguous parsing of ";" within @media block (#12923)

Also infer missing semicolon before EOF (required for @debug and @warn
at end of file)

Change-Id: Ib4449a3b8d79ce1b35732d4a33a1a30530bfc91a
Merge commit '3bfd0046eaead75e6b8cac7dc7b2d1ecceb25dc9' into master

Conflicts:
	theme-compiler/src/com/vaadin/sass/internal/parser/Parser.java

Change-Id: I6516a1f73cd2fb363407d9301f497b2e63bb92f9