Re-structure the 'Testing' language doc
Re-structure the 'Testing' language doc

Moved around sections and renamed subheadings, to make the page more
logically structured and accessible for readers.

Comparison of before/after structure: http://pastebin.com/raw/UZUMYTH1

tbrowder/doc,stmuk/doc,antquinonez/doc,MasterDuke17/doc,jonathanstowe/doc,stmuk/doc,stmuk/doc,tbrowder/doc,jonathanstowe/doc,MasterDuke17/doc,jonathanstowe/doc,perl6/doc,gfldex/doc,perl6/doc,stmuk/doc,stmuk/doc,LLFourn/doc,LLFourn/doc,dha/doc,dha/doc,gfldex/doc,MadcapJake/doc,LLFourn/doc,perl6/doc,antquinonez/doc,dmaestro/doc,MadcapJake/doc,MadcapJake/doc,MadcapJake/doc,antquinonez/doc,dmaestro/doc,dmaestro/doc,gfldex/doc,tbrowder/doc,dha/doc,perl6/doc,jonathanstowe/doc,antquinonez/doc,dmaestro/doc,LLFourn/doc,perl6/doc,dha/doc,MasterDuke17/doc,tbrowder/doc,gfldex/doc,LLFourn/doc,gfldex/doc,dmaestro/doc,antquinonez/doc,MadcapJake/doc,dha/doc,jonathanstowe/doc,MasterDuke17/doc