added mem.pct_usable and swap.pct_free as metrics #306
Made percent metrics integer values #306
changed pct metrics to 0 <= v <= 1 like other percent metrics #306
added a check to verify that linux2 is sending the pct metrics #306
Merge branch 'master' of github.com:DataDog/dd-agent into mem-pct-used
Merge pull request #334 from DataDog/mem-pct-used

Added system.mem.pct_usable and system.swap.pct_free, fixes #306
Merging