Modifying puts to logging
Add FrontMatterHandler to AsciiDoc Chain to void duplication

Fixes issue with AsciiDoc rendering the front matter as
if it was part of the source. content_line_offset handled by
the front matter handler and delegated down
assign doctitle to title attribute for AsciiDoc files

- also switch to single quotes where interpolation is not used
Merge pull request #235 from aslakknutsen/asciidoc_headers_2

Add FrontMatterHandler to AsciiDoc Chain to void duplication
Merge remote-tracking branch 'origin/master'

Conflicts:
	lib/awestruct/handlers/asciidoctor_handler.rb
Merge commit 'refs/pull/236/head' of github.com:awestruct/awestruct

Conflicts:
	spec/asciidoc_handler_spec.rb
Missed these in the last commit