Add updates to policy.markdown for 3.5
Merge pull request #318 from deb-cfengine/addpolicy

Add updates to policy.markdown for 3.5
Add changes to enterprise-api and special-variables pages for 3.5
Merge pull request #319 from deb-cfengine/addapi_specvar

Add changes to enterprise-api and special-variables pages for 3.5
Corrected link error on the enterprise api page
Merge pull request #320 from deb-cfengine/entapi_fix

Corrected link error on the enterprise api page