Merge pull request #543 from paczian/master

fixed color bug in heatmap
add error if paginated offset larger than total
update mixs metadata retrieval
fix syntax and CGI header bugs
Merge pull request #546 from teharrison/develop

bug and error handeling fixes
fix offset out of bound error
Merge pull request #547 from teharrison/develop

fix offset out of bound error
fix required options
Merge pull request #549 from teharrison/develop

fix required options
Merge branch 'develop' of github.com:MG-RAST/MG-RAST