Adding blocks for new flowers and doublePlants
Add new grassless dirt and podzol block types for 13w36
add packed ice block for 13w36
Merge Pull Request #987
Merge Pull Request #986
add red sand. move packed ice so blockIds are in order
fix double_plant image names
Merge PR #996

Conflicts:
	overviewer_core/textures.py
Merge branch 'snapshot'

Conflicts:
	overviewer_core/src/iterate.c
Bump extension version
Add Acacia/DarkOak wood
Add stained glass and stained glass panels

Note that this commit changes the pseudo-ancil-data type from unsigned
int to an unsigned short.  Our pseudoancil code creates 5 bits of data
to store adjacency information for glass.  Glass also has 4 bits for
color info.  This means we need a total of 9 bits to render these (thus
int --> short)
Fix a oops with water