Add tox and travis config file, update .gitnore.
Hold reference to prepared stmt while executing

Since we use a weak-reference dict for caching prepared
statements, we need to make sure at least one reference
is held during executing to avoid it being GC'ed.
Fix bad on_remove call on sessions, listeners
Reference prepared stmt when exec'ing bound stmt
Don't check for schema agreement when shutdown

This avoids some unneeded noise in debug logs when shutting down a
Cluster.
fix "no viable alternative at input" on map type

encode key and value of map data type with native data types' encoders
fix "no viable alternative at input" issue on list type

use native type encoders to encode elements of list
Use timeouts on all Control Connection queries

Fixes PYTHON-34
Add timeout parameter to Session.execute()
Add default timeout to Session

For PYTHON-35
Add null logging handler to cassandra package

This prevents spurious warnings like 'No handlers could be found for
logger "cassandra.cluster"'.  This will not affect normal logging.
encode inner data type of collection with cql_encode_builtin_types()
rename generic encoding function to cql_encode_all_types()
Consolidate _child_policy and child_policy
Merge pull request #59 from datastax/trivial_misnaming

Consolidate _child_policy and child_policy
s/Note/Important/ for Session.timeout docstring
remove unused cql-collection-types-in-python set
add encoder mapping for OrderedDict

OrderedDict is the resulted object type when SELECT-ing map data object.
Merge pull request #62 from yinyin/insertupdate-with-selected-map

add encoder mapping for OrderedDict
Merge pull request #61 from yinyin/collection-inner-type-convert-fix

resolve "no viable alternative at input" when insert/update with map or list which contains blob as inner types