Remove 'not found in _includes' hacks

Remove the use if "unless contains 'not found in _includes directory'"
hacks that were previously used to detect when _includes were missing.

This change is required as the hack no longer works with the latest
Jekyll release (and therefore also with GitHub).

Additional 'custom_pom_template' and 'custom_gradle_template' flags
must now be set in _config.yml if you want to include a custom pom.xml
or build.gradle file.
Add missing ZeroClipbpard SWF file

Flash support for ZeroClipboard is not working in project pages since
the SWF file is missing. There was a typo in the .gitignore file that
ignored "*.sw?" files.
Make the link to a project's forum optional

Omit the link to the forum if the project's metadata does not provide
a forum url
Remove link to forum.spring.io in billboard
Merge branch 'bclozel-gh-pages' into gh-pages
Update to RC1 release
Minor update
Fix list indentation
Fix indents
Update for 1.0 GA release
Fixed download links
Change Forum navbar item to Questions

The projects navbar should mirror the one on the spring.io website.
Merge pull request #7 from bclozel/forum

Update navbar item "Forum" -> "Questions"
Fix company name and website in footer
Merge remote-tracking branch 'ghpages/gh-pages' into gh-pages