Update build.xml for MC 1.4.6

Just changed the version numbers to ensure that the correct version of forge and MCP are downloaded
Override shouldRefresh.
Make gates and wires available for other mods in "preInitialize" phase
Merge pull request #539 from Flow86/patch-gate

Make gates and wires available for other mods in "preInitialize" phase
Merge pull request #522 from ft975/master

Updated build.xml for MC 1.4.6
Merge pull request #525 from aznhe21/patch-pipes-refresh

Pipes should not refresh.