Add new unit test.

- add speed test of fields
Field speed test of scalar values.
Modification of speed unit test.

- add test of FieldConstant
- use typedef of return type (prepare for add template parameter)
Change of speed test.

- add template parameter of fixture class
- create separate method for test of fields
- add speed test of Field::value_list method
Optimization of speed test.

- add test for vector and fixed vector values of fields
- add general method for run test loops
- add methods for set data and test results of tests
Add new speed tests.

- add unit tests of FieldFormula, FieldPython and FielElementwise
Development notes.
Modification of speed test.

- add parameter to constructors of Field objects.
- complete the FieldElemetwise test.
- modification of FieldFormula and FieldPython tests.
Add ASSERT into value_list implementations.

- Field*<...>::value_list implementations check that elements of
  result vector (value_list) has correct number of rows. This is
  necessary for variable size vectors.

- Add slow default implementation into FieldAlgorithmBase and use it
  in FieldInterpolatedP0

- use only python2.7

- use python suppression file unit tests
Fix field_speed_test

- set correct shape of values in value_list
Move profiler output of speed test to file.
Modification field speed test.

- prepare method for read input strings and set input lists.
Hints for fix field_speed_test.
Modification of speed test.

- usage regions and region sets of fields
Fix FieldSpeedTest for Python.

- Add better error checking into PythonLoader.
- fix Python sources in field_speed_test.cpp
Finish the speed test.

- finish test for Python
- set static constant variable for appropriate measurement of speed
- remove printouts to console and unused commented parts od code
Fix in speed test.

- change of profiler filename, for each template parameter of test must
be seperate file
Merge branch '1.8.0_master' into DF_speed_test
Merge pull request #211 from flow123d/DF_speed_test

Df speed test
Close #44