Timefixes final

Travis compiling is repaired:

1. Use GCC 4.8.1.
   Note:
   - 4.8.2 causes run time error.

2. Use Clang 3.5 + GCC 4.8.1 libraries.
   Notes:
   - Libs from 4.8.2 cause run time error;
   - Clang 3.6 is incompatible with 4.8.2 libs;
   - Travis used Clang 3.4 earlier: the old script did not work, it was just installing clang 3.6 and not selecting it.

3. Reduce number of compiling threads to 2 - Travis VMs sometimes go out of memory on 4 threads.