Add ability to create codemirror with merge plugin, fixes #91

[CarlAmbroselli]

This let's you use the merge plugin by adding merge-view to the directive.

Example:

<ui-codemirror
    merge-view
    ui-codemirror-opts="options"
    ng-model="editCopy">
</ui-codemirror>

$scope.options = {
        orig: 'StringToCompareWith',
        lineNumbers: true,
        highlightDifferences: true,
        connect: true,
        collapseIdentical: false
}

[LeSuisse]

I needed to use the merge plugin so I have done some functional testing of this PR. As far as I can tell this seems to work. I think it would be a good idea if these changes could be considered for integration.

[yannis-rossetto]

Hello,

Any news about this contribution ?

[goldserg]

I don't understand how to use merge plugin.

Both values (old and new) I receive from ajax ($resource), and on initialisation moment I have no values... What I should do?

html

js $scope.editorOptions = { mode: 'xml', lineNumbers: true, highlightDifferences: true, connect: true, collapseIdentical: false };

...GET { $scope.leftVar = val1; $scope.rightVar = val2; $scope.editorOptions.origLeft = $scope.rightVar; }

[goldserg]

I used hack. Wrap in ng-if and directive start only after ajax complete.