Second release branch tag for CESM2.0 release, fixing DA and tools and README files, identical to clm5.0.dev013

Update cime and cism to newer versions used in release. These bring in some answer
changes. The cime version updates the orbit for 2000 compsets. The cism version
changes answers for two fields with NO_EVOLVE and more fields for EVOLVE.

Fixes an important bug needed for use with Data Assimulation. Several changes
to testing. Adding wallclock as needed, changing a few compsets so science
supported compsets are used, added tput_tolerance to some tests known to be
variable.

Many changes to the clm tools for creating input files. Added the version by
querying "git describe" and adding it as an attribute to NetCDF files. Changes
to get tools working, and tested. Also changed so that tools can be run in either
a CTSM checkout or a CESM checkout.

Updated README files so they are accurate.