Rename LinearReaction and PadeApproximant classes.
Linear reactions and PadeApproximant cleanup.

- rename class members
- reaction matrix - replace 2d array with vectors
- clean up code
Cleanup PadeApproximant.

- remove dead code
- unify the methods with LinearReaction
- unify reaction matrix multiplication
Reactions cleanup, include cleanup.
Reuse output vector scatter in DualPorosity and SorptionBase.
DualPorosity computation scheme switching.
Enable different reactions in solid and liquid in sorption.

- introduce new keys reaction_liquid and reaction_solid
Correct input files in test23.
Merge branch 'PE_sorption_reaction' into 1.8.0_master
Clean and rename variables in DualPorosity-compute_reaction.
Introduce record scheme_tolerance in DualPorosity.
Reference manual - describe DualPorosity scheme tolerance condition.
Make macros to handle returned error code.

- make macros to handle MPI, PETSc and ASSERT error code
- add unit test
Create output directory if doesn't exist.

- move code to FilePath class
- create absolute path of output directory
- changes in unit tests
Fix computing of value in FieldInterpolationP0.

- change test of last computed element (add flag of boundary/bulk
element)
- remove flag of last computed element if time is changed
Add time dependence to field unit tests.

- modification of FiledElementwise and FieldInterpolatedP0 unit tests
Add inline function what check error.
Script for conversion from markdown to HTML.
Fix conversion between string and wstring in python loader caused by differences between python 2 and 3.
Improve continuous integration.

- add windows32 platform
- introduce PLATFORM_NAME in config.cmake
  to name inastall packages
- publishing script prepare_to_publish
- Flow123d_git_info - retrieve git information and
  set flow123d version
- all version informations are taken from branch name
- rev_num.h generated from template file