Tests for Cassandra-7281
Merge pull request #118 from marcinszymaniuk/master

Tests for Cassandra-7281
scenarios, adjust exception handling

remove unneeded conditional logic and simplify --
now a "fatal" (non-deferrable) exception will still be raised as a MultiError
so that any earlier exceptions won't be hidden.
paging tests add more scenarios for paging with limit

now includes paging using =, and across multiple partitons with 'in'
Merge branch 'master' into scenarios_with_page_limit