Adding minimal perfect hash function generation.

An implementation of minimal perfect hash function generation as described in
Czech et. al. 1992.  http://bit.ly/137iukS
Merge pull request #348 from staticfloat/devel

Bump Cairo for reintroduction of @BinDeps.install
Add REPLCompletions package
Merge pull request #349 from loladiro/replcompletions

Add REPLCompletions package
bump PyCall, replace PyPlot with PyCall-based version
bump PyPlot
bump PyPlot
Bump version of Roots package
Merge pull request #350 from jtravs/Roots

Bump version of Roots package
SymPy: sha1 bump

writemime support
GoogleCharts: sha1 version bump

add writemime support, support keyword arguments
GoogleCharts: sha1 version bump

Adjust writemime timeout
added IJulia package
bump PTools sha1
tracking julia changes to getipaddr
bumped HDFS sha1: added Blocks interface
bumped Blocka sha1: migrated HDFS and DataFrames out of blocks
GoogleCharts: sha1 version bump

fixes for writemime
Add Vega
bump IJulia
ClusterManagers: bump version for a ScyldManager fix