mantis bug #842

this version adds basic support for the newtype construct, allowing to
define internal types using the SDL syntax.
only support definition of array types:
newtype MyType
array (SomeInteger, SomeType)
endnewtype;
this will be transformed into:
MyType ::= SEQUENCE (SIZE (minOfSomeInteger .. maxOfSomeInteger)) OF
SomeType

not complete, the gpr for SDL must call opengeode to generate Ada with
all input files in one go, not one call per file

as per ISS request

- timers were missing
- tab activation was buggy when clicked from a nested diagram

Catch and report error situations better
Update help and info messages

Calling from command line:
 * Added switch --QGen, to be used together with --toC or --toAda,
   If --QGen is given, C or Ada code is generated using QGen

For calling from GUI, added menu items
 * 'Generate Ada code with QGen', shortcuts Ctrl-K or F6
 * 'Generate C code with QGen', shortcuts Crl-L or F9

taste authored Apr 26, 2018 and Daniel Tuulik committed May 17, 2018

On laptop, the + is shared with the = keys and requires a shift press.
The built-in ZoomIn event from Qt does not work with shift.

On laptop, the + is shared with the = keys and requires a shift press.
The built-in ZoomIn event from Qt does not work with shift.