forrester: fix the FlowDialog

Either the Compartment list or the Parameter list were not
coherent. Items not connected to the flow were available and
redundancy could happen. From now on proposed items are unique, and
available only if connected to the flow.(closes #26)
decision: refactoring tooltips

The informations feeding the tooltip of an activity were collected and
combined by the DrawingArea. The tooltips system was not used the
wright way. From now on, the tooltips is used the proper way, and
methods have been added in order to delegate information query to the
dedicated classes representing the Model part of the MVC design
pattern.

Signed-off-by: Patrick Chabrier <patrick.chabrier@toulouse.inra.fr>
decision: refactoring tooltips
Revert "decision: refactoring tooltips"

This reverts commit 498d8ca7bda2e40eda55a520fd83b4143c3d1506.
Merge branch 'decision' of git://github.com/Chabrier/packages
all pkgs: update according the new Package API

- take into account the curr_package parameter for Modelling plugins
- update tests using a package instance rather than the singleton
forrester: modify the variable dialog

Variables item can be edited at the same level of expressivity than a
flow item. Variables can be linked with parameters item, compartment
item and exogeneous variables.
- The variable dialog has been removed.
- The flow dialog has been modified in order to be used for variable
and flow items.
- The variable item has been enhanced to carry more information.
(closes #19, #20)
muparser: fix missing doc/CMakeLists.txt

The file doc/CMakeLists.txt is missing and the CMake process fails. So,
we add an empty doc/CMakeLists.txt.
output: restore the GVLE output plug-in

The GVLE output plug-in was removed in the previous patch. We re-enable
the code.
vle.output: fix missing gvle plugin storage

The gvle plugin storage was temporarly removed by error.
output: fix requirements for gtk+

Glade files required 2.24 version of gtk+ whereas only 2.23 version is
provided on win32.
decision : update for win32

- remove DllDefines since extension is now a static lib
- exports symbols are also removed
- add FindVLE and FindGVLE cmake scripts and rely on them for
finding vle and its gtkmm dependencies for win32
difference-equation: update for win32

- remove DllDefines since extension is now a static lib
- exports symbols are also removed
- add FIndVLE and FindGVLE scripts and rely on them for finding vle
and its gtkmm dependencies for win32
celldevs: update for win32

- remove DllDefines since extension is now a static lib
- exports symbols are also removed
- add FindVLE cmake script and rely on them for finding
vle on win32
cellqss : update for win32

- remove DllDefines since the extension is now a static lib
- exports symbols are also removed
- add FindVLE cmake script for findinf vle on win32
differential-equation: update for win32

- remove DllDefines since the extension is now a static lib
- exports symbols are also removed
- add a FindVLE script for finding vle on win32
- fix missing include (iostreams)
dsdevs: update for win32

- remove DllDefines since the extension is now a static lib
- export symbols are also removed
- add a FindVLE cmake script for finding vle on win32
fsa: update for win32

- remove DllDefines since the extension is now a static lib
- exports symbols are also removed
- add FindVLE and FindGVLE cmake scripts for finding vle on win32
- fix missing boost dependencies
petrinet: update for win32

- remove DllDefines since the extension is now a static lib
- exports symbols are also removed
- add a FindVLE and FindGVLE for finding vle on win32
forrester: update for win32

- add a FindGVLE cmake script for finding vle on win32
- fix missing boost dependencies