Bump to 1.6
Updated to leafletjs from version 0.3.0 to version 0.5.1 (latest stable).

Notable changes in leaflet:
- Adds better support for touch devices.
- Adds keyboard control of map (+/- to zoom, arrows to move)
- See https://github.com/Leaflet/Leaflet/blob/master/CHANGELOG.md
  for full changelog.
Merge pull request #20 from crussell52/master

Updated Leaflet API from version 0.3.0 to version 0.5.1
Update to latest leaflet-src (better for debug)
As of https://github.com/Leaflet/Leaflet/commit/81221ae4cd9772a8974b2e3c867d4fb35abd052d
Go to source for released 0.5.1
Partial support for v1.5 blocks
Add v1.5 activator rail and redstone comparator
Add dropper
Add hopper
Fix error in current ExtraBees (new block ID field)
Avoid building completely transparent border tiles
Changes for Forge API support
Fix errors in port to new Leaflet - breaking UI when login enabled
Update Biomes'O Plenty support for v0.4.6
Add robots.txt to keep scanners from scraping web
Add option to disable initial zoomout validate (can be expensive)
Avoid exception with undefined pipe ID with LogisticsPipes
Fix problem with initial scan disable
Handle top-on-all-sides behavior for double slabs
Enable MFR support to be used on older versions (Tekkit-Lite 0.5.7)