Refactor the blocking master documentation

Change-Id: I67e1eb66c5661f6830389189a323aa7f97e474f9
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Use the "\note" qdoc command instead of the raw "Note" term

Change-Id: If9631df1be0a164140c95b52e8537fc849709ee9
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Add a new error value called "NotOpenError"

This error message is used when the serial port parameter setters are called
even though the serial port is not open, and it should be.

The details are very similar to the previously introduced TimeoutError, as in:

1) The "\since 5.2" notion has to be added manually as qdoc has no support for
enumeration values in that regard.

2) The value itself has to be added at the end of the enumeration not to break
the binary compatibility unnecessarily. It is fine as long as the error
documentation for the end users can be kept in the order we wish to do.

Each method documentation already contains the information that the error is set
properly when that occurs, so this change can be considered as a bug fix rather
than a new feature. It is a behavior change of course just as any bug fix.

The previous operation was wrong to go ahead down to the syscalls even though
the serial port was not open. Thereby, that was a bit pointless.

Unfortunately, there is no similar error introduced for the existing QIODevice
subclasses just yet, but this term is at least inline with the open mode of
QIODevice which is "NotOpen".

For sure, when the parameter setters are called by the end user without the
device being open results false return value as per method documentation.

This change was tested on Linux with Qt 4 and then 5.

Change-Id: I1bc7309e34bdf59793f1de510866dae1bb48b539
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Fix a grammar issue of the open method documentation

Change-Id: I158a5a66af5c07d4454a559d4e5d6b7a666f43a7
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Document that the serial port parameters cannot be set before opening

Task-number: QTBUG-33774

Change-Id: I21893547ff9debc3be9f972c77ce2a306fe60d7f
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Set the NotOpenError error code also for closing

Change-Id: Iacf0235bd64bca8fbe4e2ce2c652cd89d3136b2f
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Add an "UnknownSignal" value for the pinout signals

This needs to be added to the API because there are situations where the serial
line state is unknown. The two typical use cases are:

1) The syscall cannot retrieve the state for some reason.
2) The serial port is not open.

This has been (only build!) tested on Linux (Arch) with Qt 4 and then 5.

Change-Id: I471a68b2e335b54d9a94071f08b1b31a6fb0056a
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Return in certain methods if the device is not open

This is necessary for a couple of methods because they require the port being
open for being functional. Hence, if the port is not open, they now return
properly on their own, and set the "NotOpenError" error code .

This has been (only build!) tested on Linux (Arch) with Qt 4 and then 5.

Change-Id: Ifc77bea581dd1832e188fa7562c5c1b15c0532e3
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Don't link against QtGui in cenumerator

Change-Id: Ibc730410bae66a8547733a66daa4d1dcb5808534
Reviewed-by: Laszlo Papp <lpapp@kde.org>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Add warnings to the methods requiring open serial port

Change-Id: I441dcc6c94c75ceada684262b7ab68b5c3471aec
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Eliminate the ifdef in the code for imported headers (qt4support)

As I previously wrote on Gerrit, this idea of resembling the include hiearchy
inside qt4support has two advantages:

1) The includes are well-separated for Qt 4 that are imported.

2) The code is less complex due to the non-existence of ifdefs for major Qt
variants.

The only disadvantage is that the build system got one additional line, but the
benefits outweigh that.

This has been (only build!) tested on Linux (Arch) with Qt 4 and then 5.

Change-Id: Ic33632cd0e569693a65af094479dac0a02b1a7f7
Reviewed-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Reviewed-by: Denis Shienkov <denis.shienkov@gmail.com>
Merge remote-tracking branch 'origin/stable' into dev

Change-Id: Iaef343dd542c8b4b4e62deb481559c7c1345d347