line spacing: Change the implementation so that it can be used in toolbars.

Before it was only sidebar-specific, duplicating most the sfx2 framework, and
making it impossible to be used from the toolbars.

Change-Id: Ibb382633395157602dd806052824e5275503c3e0
line spacing: Convert the ParaLineSpacingControl to .ui.

Change-Id: I81dd0d541e7f7dd3e3fb881c2c318f9adc733fde
line spacing: Make the buttons work - they set the line spacing now.

Change-Id: Ib0a08ebedbab5bfe4db196a4d22d4a08fec15f60
line spacing: Kill the "Last value" button. Close popup when used via buttons.

Change-Id: I48eabbe5e1f41f5ed015d2fa95ade5376576cac9
line spacing: "Of:" -> "Value:"

Change-Id: I7bf251d994a0f74788d4f498626db0e0663be6c8
line spacing: Kill lots of unused stuff. Rename some member variables.

Change-Id: Ia424ea0b71e64bb1133d2a02becb79d6a5ace639
line spacing: Setup the Custom value according to the current state.

Change-Id: I16d34d501385c57ba32dece1eb8032ff38d5f4a6
line spacing: Honor the current setting of units.

Plus fixes of some warnings.

Change-Id: I877e08e4b60c1b654e371c6786cc3ad33e79c583
line spacing: Finally use the reworked line spacing popup in the sidebar too.

Change-Id: I7f33a25903dec7e5aa0dc878ff5dea7f35935863
line spacing: Kill RID_POPUPPANEL_PARAPAGE_LINESPACING.

Change-Id: Ibc442d3c4fa05a47c2900d61623bd02a1b03e48f
line spacing: Unused.

Change-Id: Icf93aff540da480c7e1a66abe8a639dc6cd0ead0
line spacing: Enable/disable also the value's label, looks more natural.

Change-Id: Ifc0e26008b5b5a5bcc8343ee37b87cda3fdb6114
line spacing: Correct way of detecting the currently used units.

Change-Id: I208c54f948ecfc0a47d9b26c83acd0bbfdc2070f
line spacing: Introduce an icon for that.

Change-Id: I26922eb51120331c1f10b00e2bf59bdd7cd8d413
line spacing: Magic 'Property' that is needed to actually show the icon.

Change-Id: I65ac0dc09936ba20d42f1485d628289d1cfab819
line spacing: Some consistency.

Change-Id: I9c5e3d27c4c3333c6b76eac9acd116417db9a363