Add identify support

In the course of adding identify support, also took the opportunity to address
a few mistakes and refactor some code for future ease of development.
Return '' for identify state on read ipmi

For exploring the api, a write-only attribute presents difficulty.  Address this by allowing
plugins to return a '' value and have ipmi plugin return that value to enable things
like the web api explorer.
Merge branch 'master' of ssh://git.code.sf.net/p/xcat/confluent
Bump version number of server

Changes have occurred since 1.0, disambiguate from last release.