Metalinks Code

added date conversion functions, fixed priority to preference conversion

add size element to example

simplified code by using the Metalink4 data structure as this spec more closely aligns with v4 IETF RFC format that v3

updated for new metalink library calls

Changed xmlutils.py library to more appropriately named metalink.py, removed metalink from function names, added parsehandle function

changed generated file to metalinkc.py

added support for metalink rfc format

bugfixes for metalink4 and conversions

File extension: .meta4

ran a spell check and corrected one small issue (fallback -> fall back).