Caveclient

- Added generalized support for detecting server versions to provide timely exceptions to users
- Used new support to check that chunkegraph has updated version before using spatial bounds kwarg
on client.chunkedgraph.level2_chunk_graph
- Added support for postign and getting segment properties files to client.state

- Added serialization support for pandas.index

- Minor documentation typo fix

- Bug fixes related to table_manager interface

- Bug fixes related to table_manager interface

- Fix attrs in dataframe attributes of client.materialize results to remove numpy arrays to allow concatenation of dataframes
- Added getting multiple schemas in one call to improve initialization of table_manager interface of materialization