rethrow exceptions when running unittests, closes #154

[AlexHaxe]

refactored unittest for #181

[codecov-io]

Current coverage is 89.39%

Merging #242 into dev will increase coverage by +0.07% as of e32ce2d

@@              dev    #242   diff @@
=====================================
  Files          79      79       
  Stmts        6960    6967     +7
  Branches      284     283     -1
  Methods         0       0       
=====================================
+ Hit          6217    6228    +11
+ Partial       252     251     -1
+ Missed        491     488     -3

Review entire Coverage Diff as of e32ce2d

---

Uncovered Suggestions

1. +0.34% via .../TokenTreeBuilder.hx#1179...1202
2. +0.27% via ...ck/LeftCurlyCheck.hx#121...139
3. +0.26% via .../TokenTreeBuilder.hx#369...386
4. See 7 more...

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