Minor improvments

Some minor improvments

Python3 already works on Python/C API

In this moment, this task is done: only Qalculate and Kalgebra haven't tests at all (but this backends almost not supported), and lua have only few tests (but lua don't work correctly with command queue, so without solving this, adding more tests is pointless).

Rename Session::forceVariableUpdate to Session::updateVariables() and minor improvments

• Session::variableModel starts return DefaultVariableModel (add variableDataModel() for compatibility with KAlgebra)
• DefaultVariableModel signals for added/removed variables/functions connected to DefaultHighlighter corresponding slots

Fix errors with finishExpression
Now, all tests passed

Tests, in this moment, fails, but i fix this soon.

Add Session::finishRunExpression and move code for variable modele updating (and expressions finishing) to Session

Fix problem with MaximaVariableModel::functionsNames()

Minor improvments

Minor improvments

In D16806#358163, @apol wrote:

Maybe it would make sense to use the SyntaxHighlighting framework?

Actually, we already use KSyntaxHighlighting, but still only Repository class. We plan rewrite our highlighting code on KSyntaxHighlighting, but we support adding new variables and functions in runtime for different sessions and backends, and as I know KSyntaxHighlighting don't have features for adding new variables and functions, so it is not very easy and we are planning start work on this after 18.12

Maybe it would make sense to use the SyntaxHighlighting framework?

Well, @filipesaraiva, I hope, that you have read my message and you don't write answer, because you haven't objections.
The release is soon and Alexander agree with this patch, so I merge this patch to master.
We could return to this theme later, after 18.12, if needed.

So, @filipesaraiva, what do you think about it?
We plan to merge this code to master November 7, if there aren't objections.

Small improvments (change else if to else)

Added cyclic moving for tabs

Some code improvments

Remove entry cursor reseting (on master already)

• Allow double click in readonly mode
• Fix bug with existing assistant, when we load read-only worksheet from empty worksheet with existing backend
• Fix bug with existing entry cursor, when we load read-only worksheet from empty worksheet with existing backend

Another improvments

Fix bug with load

Add availability check for default session

Some improvements

Improve subprompt handling

Rewrite the patch according new @asemke changes

Replaced setResult by addResult in PythonExpression::imageChanged().

This resulting code looks ugly, so @asemke, @filipesaraiva I am open to suggestions.

Comment's changes and some small text fixes

In 610f8c8ec70b4b52a3f4487c3348b87b66a0b85f I have added autocompletion by native Python autocompletion.
It's work for variables, functions, modules, even for class methods and fields.

Add support for latex typesetting