Add new parser tests to increase test coverage.

Also remove the non-functioning precedence climbing implementation and
limit the number of iterations in the test for chained field accesses
(unit tests are supposed to be fast, and that test took several
 seconds.)
Fix EOF character being displayed in premature EOF errors
Merge pull request #73 from jspam/029-parser-test-coverage

Add new parser tests to increase test coverage.
Move LineReader.eof to its companion object and use it for error msg
Merge pull request #76 from TehMillhouse/EOF_msg

Fix EOF character being displayed in premature EOF errors
Basic AST