Fix bug in Well44497a, Well44497b and clean up syntax in all Well PRNGs

1. Fixes a bug in Well44497 parenthesing:
  `val z0: Int = (state(map(R_1)) & LowerMask) | (state(map(R_2) & UpperMask))`
should be
  `val z0: Int = (state(map(R_1)) & LowerMask) | (state(map(R_2)) & UpperMask)`

2. Comments out unused parts of the WELL algorithms (defined yet unused in the original algorithms).

3. Removes unused imports.

4. Cleans code syntax up (makes code pass IntelliJ IDEA inspections).