Madgui

- refactor and simplify treeview data model, more cohesive table definitions
- monospace in tables
- autosave and restore online settings (MEFI)
- fix missing QUndoCommand.setObsolete on Qt<5.9
- allow defining a ``limits`` parameter in multigrid config
- fix IndexError if too few monitors are selected
- implement missing export functionality in orbit/emit dialogs
- use ``data_key`` for initial conditions im-/exports
- add import/export menus as in mirko
- implement strength import from YAML
- refactor import/export logic
- set YAML as the default filter in strengths export
- recognize '!' comment character in .str files
- fix treeview edit spin boxes to fit into their column
- highlight changed items in SyncParamWidgets (read/write strengths)
- highlight explicitly specified beam/twiss parameters in bold (initial
conditions dialogs)
- code deduplication among diagnostic dialogs: share same rowgetter method
- save selected monitors for orbit/optics in different lists
- support QTableView again in parallel to QTreeView, this has some advantages
such as supporting background colors
- highlight changed steerers in bold in multigrid dialog)
- rework the optic variation dialog, based on tableview, added automation UI
- disable section highlighting in TableView
- refactor how variables are stored in orbit correction dialogs
- always show the current value versus the "to-be-applied" value in the
"steerer corrections" table
- add back/forward button in orbit correction dialogs
- nicer arrow buttons (QToolButton) in element info dialog
- show monitors during orbit correction

- fix log widget to have monospace on windows
- fix exception when setting max log size via menu
- fix exception in corrector dialog when using MATCH or sectormap methods:
"TypeError: macro() missing 1 requried positional argument"
- fix TypeError in corrector dialog when changing config (combo box):
"TypeError: itemText(self, int): argument 1 has unexpected type 'str'"

- fix mass unit in MAD-X
- massive simplification of knobs API for interfacing control system
- can read beam parameters from online plugin
- show updated orbit plot after fitting in orbit-correction-mode (regression)
- open orbit plot for orbit-correction-mode

- Add constrain to the match feature. If the residual is too high, then the
optics are not changed

- fix TypeError: set_draggable() missing 1 required positional argument
(in shared plot mode)
- add units in curve y labels
- change some quantity labels
- separate function to edit model parameters, for use in plugins etc

- fix exception when opening matching dialog
- fix bad fit_range leading to bad initial conditions fit
- add safeguard for ``None`` offsets in corrector widgets
- restrict orbit correction to only X/Y constraints
- let user choose whether to fit the difference between measured and design
values or just fit the design value directly (this can be different in case
the backtrack does not describe the monitor values very good)