Add data store interface and default implementations
Add getDataStore() method to XProcRuntime
Read http data and documents using the runtime httpclient and datastore
Use runtime httpclient/datastore for xinclude and other library steps
Support zip, css, and properties files over runtime httpclient/datastore
Remove unused getFile method
Use runtime datastore for fileutils to support virtual file systems
Merge branch 'saxon95' of github.com:jamesrdf/xmlcalabash1 into datastore

Conflicts:
	src/com/xmlcalabash/extensions/Unzip.java
	src/com/xmlcalabash/extensions/Zip.java
	src/com/xmlcalabash/library/Store.java
	src/com/xmlcalabash/library/XInclude.java
Removed unnecessary import statements
Attempt to fix issue #135 by removing bogus references to URI schemes
Added pxp:set-base-uri extension step
Fix some local directories
Fix bug in pxp:set-base-uri where the base URI of descendant nodes wasn't changed; refactored TreeWriter a bit
Attempt to fix issue #139; if a parameter wasn't initialized with a general value, create one from its string value
Fix issue #137; make base URI and static base URI configurable for better integration into eXist
Fix bug where, in the case where multiple steps are set on the command line, the implicit pipeline construction always fails.
Fix issue #140 by making sure that if a saxon-configuration file is specified, the parser settings it contains trump any parser settings requested elsewhere. As a consequence, attempting to request an HE parser when your saxon configuration specifies an EE parser will mean you get an EE parser. Don't do that, if that's not what you want.
Merge branch 'datastore' of https://github.com/3-Round-Stones/xmlcalabash1 into 3-Round-Stones-datastore
Avoid NPE when log.getParent() returns null
Parameterize for multiple versions of Java