Move template processing substitutions to TemplateProcessor
Check that location is not null before adding to substitutions
misc improvements, mainly to locations -- BrooklynImageChooser can now be subclassed to inject custom logic more easily; 64-bit can be selected as a config key; and misc cleanups
Added native transport port configuration for Cassandra
Change executeScriptHere to executeScriptAsync as in other entities
Add nativeTransportPort entry to test class
Merge pull request #1092 from grkvlt/fix/cassandra-native-port

Tests pass and build ok, merged
Merge pull request #1085 from grkvlt/fix/template-processor-substitutions

Added null check as suggested. Merging.
more detail in description of OS_64_BIT to reflect underlying jclouds semantics
Merge pull request #1090 from ahgittin/master

misc improvements, mainly to locations
tweaks to permit easy subclassing of cassandra entities to support cassandra distros
misc tidies to improve use of locations
fix finalization log message
Jsonya toString generates valid json
cassandra unpacked dir code review
Merge pull request #1091 from ahgittin/feature/cassandra-tweaks

cassandra tweaks and misc