Updated the cython header file with information about FMI2 support in FMIL. Related to ticket:2578
Load_fmu() handles fmu 2.0 with new input-argument
Load_fmu() removes temp directory more often
#2582

Class renamed from BaseModel to ModelBase.
#2645

Methods for FMUModelBase2:

init (re-unpacks the xml)
set/get methods implemented (not yet working)
logger-functions
Model-information methods
Merged pyfmi trunk to development branch for fmi2. Related to ticket:2646
#2647

Log-functions writing/reading to file in FMUModelBase2 implemented
#2720

FMUModelBase 
 *most of the methods implemented
 *still missing methods for derivatives 
 *still missing ability to save FMU-states

FMUModelBaseME2 methods implemented 
 *still problem with simulation

FMUModelBaseCS2 methods implemented 
 *can successfully simulate CS-model
#2720

Methods implemented in 
-FMUModelBase2
-FMUModelME2
-FMUModelCS2

to cover the methods listed in FMI 2.0 spec,
functions providing partial and directional derivatives
not completely implemented.
#2677

Remaining functions in FMUModelBase2 
for FMI 2.0 support implemented
related to: #2677

Merged the development branch for support for FMI 2.0 in PyFMI to the trunk

New classes introduced to cover the support for FMI 2.0
-FMUModelBase2
-FMUModelME2
-FMUModelCS2

Minor help classes introduced to make the three above to work
-ScalarVariable2
-FMUstate2

Help function used to load and connect a fmu
-load_fmu2