Order of index.jl and datavec.jl was backwards
Float no longer exists
Added an SVD method for DataMatrix objects
Add test for UTF8Strings and PooledDataVecs.
Add serialization wrappers: save and load_df.
Add string() for AbstractDataVecs.
Change PooledDataVec to Uint32; add utilities.
Add tests for PooledDataVec helper functions.
Add tests for UTF8String support.
Add extra PDV constructors.
use do-block syntax for file open

I fought long and hard for the do-block syntax.
Merge pull request #56 from StefanKarpinski/patch-1

JMW's SVD demo, and SK's use of do-block syntax for file open
Use deepcopy for DataFrame's
Small bug fix.
Revert back to using Uint16 for PooledDataVecs.
Merge pull request #55 from HarlanH/pooledvec-interface

Pooledvec interface functions
Added multicolumn DataFrame assignment to fix #51.
Small name change.
Bugfix: renaming Index groups.  Add helper function for DataFrames.
fix macro-expansion and expression stringifying changes