Completion for Apex and Visualforce references in other metadata files

[Scott Wells]

Add completion support for Apex declarations/references and Visualforce page names in other metadata files such as .object, .layout, etc., files. Also add support for formula functions in key areas such as validation rules in .object files.

[Scott Wells]

This should also include completion for the various XML documents of other metadata, e.g., .layout, .object, etc. I should be able to produce XSDs for these based on the metadata API WSDL/generated client classes since those match.

[Scott Wells]

FYI, the next released build (1.6.9.4) will include an XSD for validation and completion in Salesforce metadata XML files.

[Scott Wells]

Partially delivered in 1.6.9.4.

[Scott Wells]

This is going to be critical for things like refactoring. All references to a given name must be tracked or they'll be missed during renames, safe deletes, etc.