RrdGraph.js: make HRULE support reference to variable

The value of HRULE could be a reference to for example a VDEF variable.
Merge pull request #10 from pommi/hrule-variable

RrdGraph.js: make HRULE support reference to variable
Fix flags parsing (options without a value)

Also fix some typos and white-space issues. Reported at
https://github.com/pommi/CGP/issues/88
Merge branch 'Lekensteyn-fixes'
Fix textalign name typo. Thanks to Poil
Check when this.gdes[i].legend is null
Fix ident. Thanks to Poil
Upgrade to javascriptrrd ver 1.1.1
Fix get reponseText in FetchBinaryURL
Merge branch 'master' into gh-pages