Attributes GH PR #764: https://github.com/ArcticaProject/nx-libs/pull/764

This fixes the verification in validateSpec()

Attributes GH PR #761: https://github.com/ArcticaProject/nx-libs/pull/761

If nxagent is started in fullscreen mode take care the saved size
(that is applied on exit of the fullscreen mode) will be configured
correctly. Also respect a user provided -geometry option (had been
ignored here previously).

Fixes ArcticaProject/nx-libs#449

There's no need to reduce the size to 75% in rootless mode. We always
want to have the full size then.

Fixes ArcticaProject/nx-libs#757 (Part 2/2)

... by using some short named variables and the min() macro.

No change in behaviour.

Minor fix: The loop always started at index 3, comparing against the
value at index 2. So the resolution at index 1 (320x240) was never
taken into account for anything.

This solves weird window (menu) placement and drawing behaviour on right/lowest
25% of the screen.

Fixes ArcticaProject/nx-libs#757 (Part 1/2)

Attributes GH PR #754: https://github.com/ArcticaProject/nx-libs/pull/754

This fixes an assertion being triggered on reconnect:

assertion=assertion@entry=0x7f2f0bba6510 "(dpy->flags & XlibDisplayPrivSync) != 0", file=file@entry=0x7f2f0bba62fc "XlibInt.c", line=line@entry=895,

Attributes GH PR #744: https://github.com/ArcticaProject/nx-libs/pull/744

If X2go runs in auto keyboard mode it will pass keyboard=null/null to
the agent and set the keyboard afterwards with setxkbmap. This patch
lets nxagent handle that situation internally (null/null will be
interpreted as clone) and disables X2go's mechanism (by creating a dir
that effectively blocks it; see x2gosetkeyboard)

This is only activated if the agent is run as "x2goagent".

Fixes ArcticaProject/nx-libs#368

Attributes GH PR #743: https://github.com/ArcticaProject/nx-libs/pull/743

This avoids some roundtrips.

Add possibility to pass more than model and layout via the keyboard parameter.

Specifying -keyboard clone (or keyboard=clone in options) will clone
XKB keyboard from the remote x server. This way many keyboard problems
will hopefully never return...

Should be the default but is not (yet) for compatibility reasons.

Fixes ArcticaProject/nx-libs#373

(except the "do autoconf if no keyboard is provided" feature.)

References:
  ArcticaProject/nx-libs#240
  ArcticaProject/nx-libs#368

Attributes GH PR #742: https://github.com/ArcticaProject/nx-libs/pull/742

It may not fully fix the issue mentioned below but it does for the
-keyboard commandline option at least.

Fixes ArcticaProject/nx-libs#741

Describes a check we are not doing here anymore...

we have changed that to base some time ago.

It will now create better working config files.

References:
  ArcticaProject/nx-libs#239
  ArcticaProject/nx-libs#368

avoid mix of 'variant' and 'variants'

we'll need the remote xkb in KeyboardProc in future so let's move it up.

Attributes GH PR #751: https://github.com/ArcticaProject/nx-libs/pull/751

(partially) fixes ArcticaProject/nx-libs#666

(partially) fixes ArcticaProject/nx-libs#666