Merge remote-tracking branch 'laf/issue-laf-85' into issue-laf-85
Tidy API entry points & doc; error if something other than image/png is asked for from portgroup graphs
Merge branch 'issue-laf-85'

Conflicts:
	html/api_v0.php
	html/pages/api-docs.inc.php
doc: Clean whitespaces in documentation
doc: Update markdown flavored syntax (using linguist)
Merge pull request #353 from sbadia/markdown-flavored

Use markdown syntax on agent and billing documentation