Improve checks for COLLECTIVEACCESS_HOME.

+ -v checks whether the variable is defined.
+ -d checks whether the contents of the variable represent a valid path, which
  is also a directory.
+ Therefore -v should come before -d, especially when `set -u` is in effect.
Merge pull request #28 from leftclickben/ImproveCheckEnvironment

Improve checks for COLLECTIVEACCESS_HOME.
Test installation profile with `caUtils install`

+ Simple test script which installs to a database, which is expected
  to exist but to not contain any CA schema.
+ More work to do to setup and tear down the test.
Dev script to reset CA database.
Per-user configurations for reset-ca.

+ Use $USER to load a specific configuration file containing all
  defaults for reset-ca.
Merge pull request #30 from leftclickben/ResetCaDevScript

Dev script to reset CA database.
Merge pull request #29 from leftclickben/TestInstall

Test installation profile with `caUtils install`