For loops with no assignment are no longer syntax errors. For example,
this is now valid:
for ( ; i < 10; i++) { ... }
Corresponding changes to lsl.{lexer,parser} in r99 in opensim-libs.
Fixes Mantis #2501. Fixes Mantis #2884.
It's good practice to isolate unit tests so their outcome (pass/fail)
does not depend on whether another test has been run/passed/failed. A
method is used to populate the DB independently for each test, and a
TearDown method cleans up the database after each test.
Also adding extra comment in C-style comment test.
