Fix #57

Current implementation of Embedded Node.js Features is based on features where
'Supported Environments' are not specified. As a result all Embedded Node.js 
features are present in the list of available features when tern repository is
selected in Eclipse 'Install New Software dialog'

This fix collect platform cpecific node.js distributions inside one feature 
that provides 'Suppored Environments' information so checkbox 'Show only s 
oftware applicable to target environment' in Eclipse 'Install New Software' 
dialog' can use this information.

The new tern-server-nodejs-embed-feature feature gets new description so it is
clear what platform configurations are supported.

Missing linux/gt/x86 and macosx/carbon/x86 are provided as well to cover all 
combinations of OS. WS Arch mentioned in 'Supported Environments'.

Name for win32/win32/x86_64 node.js bundle fixed to follow the same name 
pattern for other platform specific bundles.

Platform specific features were removed, because they are not needed anymore.

This fix also adds description to tern-server-nodejs-feature to make it clear 
to install rihno or embed node.js features to have tern running out of the box
or configure local server installation in preferences.