Additionally ignoring XText intermediate files
Updated release process
 - Moved org.archstudio.releng.* plugins unrelated to release engineering to org.archstudio.pde.*
 - Created target platform (actually features) definitions for Eclipse 4.3, 4.4, and 4.5
 - Updated build to install buckminster only if it is not already present
 - Updated component.rmap to optionally use an update site for ArchStudio
 - Split component.cquery in to a binary and source version