Release 2.1.0

Summary:

This release adds Gentoo osfamily support and minor plugin changes

Features:

- adding Gentoo support
- tcpconn plugin: $localports and $remoteports can me left undef if $listening is not set
- unixsock plugin: Implement the "DeleteSocket" option.
- add reportreserved parameter for df plugin
Merge pull request #146 from pdxcat/release_210

Release 2.1.0