extract time conversion into a singleton object
initial version of Describe Metadata support but for objects of Tooling API
refactored getValueMap to make it easier to use
initial version of --action=saveModified
fix problem introduced in refactoring 2 commits ago

not all files have xmlType
not all Tooling API types have prefix
fall back to DeployModified when SaveModified encounters unsupported payload
when saveModified is successful we should report success explicitly
when checking if fail is supported for --saveModified use types we are really supporting
make "saveModified" poll wait time configurable, like deployModified
added "saveModified" support for ApexComponent