Merge pull request #35 from snoyberg/master

Fix ambiguous catch for GHC 7.4
Bump version to 0.4.5.2
Actually fix the docs link
Try enabling hpc-coveralls
Trigger travis build & hopefully coveralls too
Add .gitignore for hpc temp files
Call TestImports tests & use withConnection

TestImports was not being called and showed up as uncovered in
coverage reports.  I didn't mean it to be runnable originally, but
let's just run it to make it go away from the uncovered list.
Remove withConn from tests
Add tests for Null param conversion
Extend FromRow/ToRow instance testing to longer tuples
Fix types in error messages
Fix typos in test assert strings by removing them
add code coverage status badge
Exclude test directory from coverage results
Add a trivial coverage test for Query
Add ToField instance tests for fixed width ints
Add FromField instances for Int8, Word(8-64)

Word instances were missing altogether in FromField, even though they
were present in ToField.  Add them for orthogonality.
Improve tests for To/FromField int and string instances
Add Changelog entry
Add tests for composite type operator