Migrating data-converters out of zorba core

*csv module
*base64 module
*html
Removed base64 module
Updated to the trunk version for Zorba r10237.
Updated to the trunk version for Zorba r10237.
Added Secondary Dependencies
Fixed Errors in tests
Fixed Mantis Bug[0000133]
Use PROJECT_SOURCE_DIR instead of CMAKE_SOURCE_DIR to support building inside
a Zorba project.
More changes to fix Mantis Bug[0000133]
Removed Temporarily External Module Config
Fixed Compiling Error with ERROR_PARAMS

Added MACRO to work with expath's http-client
Remove SET_EXTERNAL_MODULE_CONFIG() (done automatically by ZorbaUse now).
Base64 module moved out of zorba's core.

Changed base64 URI to http://www.zorba-xquery.com/modules/converters/base64
added missing test for base64
Removal of deprecated string functions.
New string functions.
Adding Xslt support.
Adding windows cmake module for finding libxslt.
Moved json module out of zorba's core
Changed tests, so if module isn't build module's tests aren't added