use more idiomatic first-pair syntax in BUILD
Refactored connection string parsing in order to add tests unreliant on MongoDBTest. Parsing needs work
Improve validation of URI parsed parameters.

username and db_name must be defined and non-empty.  password can be
empty.

Previously, all those values had to be true, which is overly
restrictive.
get DatabaseError message from $err if errmsg doesn't exist
test parallel scan on empty collection
refactor MongoDBTest to have user request a new client by default
PERL-166 Fix tailable cursors with no results
fix t/regexp_obj.t to use new database for each run
make local orchestration harness return non-zero exit on command failure
PERL-387 added retry logic to Database::database_names()
PERL-387 amend retry logic
PERL-130 Improve connection string support
updated Changes
fix tests for when a mongod is not running on localhost
extend default query_timeout during testing

Also fixes the related test to use the actual default via
$MongoDB::Cursor::timeout.
add escape hatch to exclude JIRA ticket from Changes file
disarm is_trial
Commit Changes and bump $VERSION
rearm is_trial
skip tests when mongod not running