fixed example template file extension
scripts to setup and test asciidoc files, howto for README
Merge pull request #346 from zclj/patch-2

fixed example template file extension
Normalize source-block types, fixes #345.
Merge #347
Updates to asciidoc scripts and instructions

* Move scripts to script/asciidoc
* Re-organize instructions in README.md
  * Bump section up from being a sub-section of contributing
  * Tidy up language
  * Add separate section on for pre-reqs.
* Clean up the bootstrap_osx.sh script (and rename it).
  * Always wrap vars in quotes (convention)
  * Use "command" or "test -x" -- was failing on my machine
  * Make SOURCE_HIGHLIGHT_DIR overrideable, mine is in a different
    location
  * Backup lang.map
  * General conventions sweep