Added cr.host module

This new module contains all global data about the current host.
Fixed memory collector for OS X Mavericks (Issue #85)

Now, Apple uses the WKdm algorithm to compress the memory, and the vm_stat command had been updated with new types of memory pages.
Updated NEWS file for #87 (New host module and fixed memory collector for OS X 10.9 Mavericks)
Removed useless comments
Modified Pull Request number (#87 to #88) in the NEWS file.
Merge pull request #88 from CentralReport/fix-mavericks-memory

New host module and fixed memory collector for OS X 10.9 Mavericks
Updated version number and release date for 0.4.0
Merge pull request #89 from CentralReport/release-0.4.0

Release 0.4.0