Error messages are displayed using the following methods:
* **zenity** parses pango markup and replaces escaped characters
* **kdialog** replaces (some) escaped characters
* **gtk-dialog.py** replaces `\n`
* **printf** interprets format strings and replaces escaped characters
* **echo** just displays the text
The error messages themself contain escaped characters and paths from variables.
This PR unifies the behavior by:
* Use **printf** to format error messages and replace escaped characters
* Setting `--no-markup` for **zenity** to disable pango markup and escaped characters
* Remove `\n` replacement from **gtk-dialog.py**.
* Use plain **echo** instead of **printf**
Use **xargs** to pass results of **find** instead of word splitting. Word splitting fails when filenames contain white spaces (or if no files are found).
To prepare them for documentation generation.
Also added descriptions to SpriteSequence implementations and their properties.
Also made a few code style fixes.
Two different issues were causing a path search to not explore cells in order of the cheapest estimated route first. This meant the search could sometimes miss a cheaper route and return a suboptimal path.
- PriorityQueue had a bug which would cause it to not check some elements when restoring the heap property of its internal data structure. Failing to do this would invalidate the heap property, meaning it would not longer return the items in correct priority order. Additional tests ensure this is covered.
- When a path search encountered the same cell again with a lower cost, it would not update the priority queue with the new cost. This meant the cell was not explored early enough as it was in the queue with its original, higher cost. Exploring other paths might close off surrounding cells, preventing the cell with the lower cost from progressing. Instead we now add a duplicate with the lower cost to ensure it gets explored at the right time. We remove the duplicate with the higher cost in CanExpand by checking for already Closed cells.
Prior to ef44c31a72eab61a597cf539ee4b138e94b254fe, Locomotor would be earlier in the trait initialization sequence than SpawnStartingUnits. After this commit, the initialization sequence was perturbed and SpawnStartingUnits would initialize first. When SpawnStartingUnits would query CanEnterCell this would generate a null reference as Locomotor had not yet initialized.
SpawnStartingUnitsInfo is made to initialize NotBefore LocomotorInfo to enforce the required trait ordering.
