created a shared library for test_page

moved pageloader_test to use it
updated pageloader_test to use compact config (like web driver test)
align file naming w/ contained class
enforce test run from the root of the project
breaking each test into its own library

allows easy running of independent dest set via dart test/src/[test name].dart
Merge pull request #16 from kevmoo/master

A lot of test cleanup
StringDecoder has been removed and replaced by Utf8Decoder
Merge pull request #19 from zachconrad/master

StringDecoder has been removed and replaced by Utf8Decoder