Update to 3.8 git version to move from Qt4 to Qt5

unreleased

• 1. Fixed
     1. Project Scope
• boost::posix_time::[milli]second takes integer numbers, and we now at least cast the floats to integers, as Boost 1.67 forced us to realize we're (incorrectly) using floating point her
• CMake: using regex to match compiler against "Clang" now enables correct build on OS X
  1. GRC
• Fixed GRC bug which broke WX and Qt (by altering the template code), in multiple (less than awesome) steps
  1. gr-analog
• fmdet_cf's derivative coefficients were wrong.
  1. gr-blocks
• float_array_to_int: int32 limits were wrongly hardcoded.
• Fixed the undefined behaviour happening in float_to_complex when accessing the second input_items element in the single-input case

• 1. Added
     1. gr-analog
• QA for complex cosine
  1. gr-utils
• gr_modtool now with autocompletion candidates for rm

• 1. Changed
     1. Project Scope
• Removed cppunit from all unit tests, replaced by Boost
• Removed the cppunit dependency