Implementation (not finished) of wells_equal, well_controls_equal, and tests. To build a WellsManager test for old and new parser

Conflicts:
	CMakeLists_files.cmake
Added test_wellmanager which loads wellmanager from deck and tests many values.
Added test calls to wells_equal() and well_controls_equal().
Extracted everything related to well controls to separate header well_controls.h - to simplify introducing new parser.
Moved well_controls implementation to separate file well_controls.c.
Removed struct WellControlManagement and replaced with simple integer field cpty in the WellControls structure.
Removed #include <opm/core/well_controls.h> from wells.h and inserted explicit #include <opm/core/well_controls.h> where needed.
Added well_controls_get_xxx() and well_controls_set_xxx() functions. The well_controls_reserved() function is called from well_controls_add() and not explicitly.
Reimplemnted struct WellControls access to use the set/get functions in well_controls.c
Temporarily added symbol HAVE_WELLCONTROLS before including well_controls.h - to get acces to the internal elements in struct WellControls.
Using well_controls_get_num() and well_controls_get|set_current() in WellsManager
Changed test_wellsmanager to use well_controls_get_xxx() functions.
Changes test_wells to use well_controls_get_xxx() functions.
Added new functions to set target and type and invert value of current control.
Using new function well_controls_invert_current().
Added new function well_controls_iset_distr().
Implemented well_controls_add_new() with well_controls_iset_xxx() functions.
Implemented well_control based on well_controls_iset_xxx() functions.
Implemented well_controls based on well_controls_iset_xxx() functions.
Added functions to get type, target and distr of *current* control.