Merge pull request #58 from dcjones/master

Use Type instead of DataType.
Clean up dataarray.jl code

Drop DataArray constructors that don't match Array constructors
Fix conversion methods to do work previously done by constructors
Add basic per-function documentation
Merge pull request #56 from JuliaStats/jmw/badDA

Drop DataArray constructors that don't match Array constructors
Change Stats to StatsBase
Add data and pdata functions as short aliases for convert calls
Convert tabs->spaces in literals.jl
Implement Tim Holy's suggestion of indexed isna() method
Add append! method for DataArrays and PooledDataArrays.
Merge pull request #64 from dcjones/append

Add append! method for DataArrays.
Fix REQUIRE to match METADATA
Fix (c)transpose for arrays of non-bits types and implement conj
Add LICENSE.md
Merge pull request #70 from JuliaStats/license

Add LICENSE.md
Merge pull request #68 from JuliaStats/sjk/transpose

Fix (c)transpose for arrays of non-bits types and implement conj
Fix test failures due to svd positional->keyword arg change

See julialang/Julia@186287a2a891baf0edf658220b43e3077af00904
Fix bit operators with BitArrays and add tests
Remove copy! definitions

There are generic copy! definitions in Base and this is not going to be
faster than the generic implementation, so I don't see a reason to keep
it. At some point we might want faster definitions for DataArrays, but
for now this fixes the ambiguity warnings.

Fixes #74
Merge pull request #75 from JuliaStats/sjk/copy!

Remove copy! definition
Fix #76

Note that I made AbstractDataArray inherit from StoredArray instead
of AbstractArray, since both DataArray and PooledDataArray are
StoredArrays. DataArray should probably inherit from DenseArray, and
the inheritance should probably be on those types and not
AbstractDataArray, but we don't have multiple inheritance, so this
seems like the way to go for now.
Generalize isna to any index set