Improve TestArithmetic2 testcase output

See the discussion in issue #69.

Removed the compilation timeout

Added a test case for the failure in group 3

Fix exec/array_of_references testcase

Add a test verifying array cell sizes

This bugged out for us.

The infinite loop test cases are hard to maintain and
are therefore removed.

And fix test timeouts.

Add draft of new bench mode for simple benchmarking

Rename Fibonacci.java to fibo.java

Because some file systems do not like files with identical names (when not paying any attention to the case)

Fix #59

Fix #52

Rename use_variable_after_declaration_in_same_statement_without_init.invalid.mj to use_variable_after_declaration_in_same_statement_without_init.mj

Fix looping test regression due to a.out

Adds rejection test for int x = x + 1;