pygr: PlotAxes: Make viewport mandatory (API change).

The viewport attribute has been made mandatory to avoid different
viewport settings between Plot and PlotAxes objects. Even though the Plot
object sets the viewport on the PlotAxes object when the axes object has
been added with addAxes this can lead to wrong results, e.g. in the
following case. If there are calculations relying on the current viewport
in the PlotAxes object before this has been added to a Plot object and
no default viewport has been used the viewport for the Plot and the PlotAxes
object differs.

Change-Id: I66f025bba3939e07912d2fd239835e5e11eb5b2b
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/85
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
setup.py: Fix regressions for win32 introduced by alpha blending.

Missing library msimg32 for libGKS.

Change-Id: Idc98d8b3d2e9b8ac69ea65cd1be2c49ec408b6ad
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/87
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
Reviewed-by: Josef Heinen <j.heinen@fz-juelich.de>
setup.py: Do not include GKSTerm build directory in sdist.

Change-Id: I3a05d36f901242caf4205f0b63d640da62c99fad
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/88
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
Reviewed-by: Josef Heinen <j.heinen@fz-juelich.de>
Versioning: New dynamic generated version module gr/_version.py.

setup.py: Use vcversioner version 2.14.0.0 bundled with gr.

In order to have the same version number 'everywhere' use vcversioner.
Bundled with gr - _no_ additional dependency.
vcversioner generates a version.txt file which will be used for source
code distributions, e.g. tarball. For installations from version control
systems it uses the information from the corresponding system, e.g. tag
in case of a git repository. The version module gr._version will be
automatically generated.

Makefile: [jh] Added 'version' target to Makefiles and helper script.

Change-Id: I045d10ae9ddf5009a8b45d84f73846384012b1a1
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/86
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
setup.py: Changed deployment target for OSX to 10.6.

Change-Id: I2068d4af7ac165e43cd7ce0c1d60e90993840292
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/90
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
pygr: Text: Calculate bounding box outside drawing routine.

Added textonaxes example.

Change-Id: I9b91daf9b320576543973fab954dc9cb2709f796
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/80
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
Use version tags for Sphinx documentation / conda build

Change-Id: Ic198f56f692887760d90889885f0b3497ffb0f99
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/91
Reviewed-by: Josef Heinen <j.heinen@fz-juelich.de>
Removed wrong gr._version import

Change-Id: I8758f8737f02a25a54c3d1b5d284430621e937b5
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/92
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
Reviewed-by: Josef Heinen <j.heinen@fz-juelich.de>
Added HTML5 logical device driver
html5: fix typos and remove trailing white-spaces.

Change-Id: I794097e2d31e9f571da9c425c88da762156aebd5
Reviewed-on: https://iffwww.iff.kfa-juelich.de/review/93
Reviewed-by: Christian Felder <c.felder@fz-juelich.de>
Reviewed-by: Josef Heinen <j.heinen@fz-juelich.de>