Converted atest/README and utest/README to reST.

Both actually were (mostly) valid reST already so the biggest change
was renaming files to use `.rst` extension. The commit also contains
some fixes to syntax and small enhancements to docs.
atests: New functionality to verify expected errors using glob pattern.

Now expected error can be specified using `FAIL GLOB:` in addition to
`FAIL REGEXP:` and `FAIL STARTS:`. The motivation was to ease matching
more complex or changing errors without needing to use regexps.
Glob patterns are simpler and, most importantly, require less escaping.

Pull request #1776 provides a concrete use case for this functionality.
removed doc/examples/using_c that was already moved to https://bitbucket.org/robotframework/cdemo
Removed very old and really bad examples.

Demo projects linked from robotframework.org and examples in User
Guide and library docs are much better than these.
Removed outdated doc/java/. Currently Javadocs are under doc/api/_static/javadoc/.
Merge commit '181c618f57236ecc7678f9510d289d96a541dcdb' into fuzzy-keyword-matching
FAIL REGEXP: -> FAIL GLOB: