Allow more flexibility to move-attack command

[mimo]

Presently, in move-attack mode, units will attack all enemy entities along their path. It would be nice to be able to select what kind of entities should be attacked (for example ignoring structures can be useful). Here is a patch to do that. It is complete for what concerns the simulation (including AIs that will benefit from it). For the gui part, I can think of adding some keys: for example if U is pressed during the move-attack CTRL-click, only units will be targeted, and if B is pressed, only buildings. More combinations could be added if felt necessary. But may-be there are some better ideas ?

[leper]

I'd make the target classes required (still keep the check if it is set), but add something like ["Unit", "Structure"] to the GUI code.

And add a different hotkey to only target Units instead of everything. (Probably ask on the forums)

[mimo]

Thanks for the comment. I'm going to commit it with the suggested changes now as I need the changes for the AI, and we can still improve the gui later. By default (i.e. with CTRL), we have ["Unit", "Structure"], and with CTRL+Q we have only Unit.

[mimo]

In 15671:

give possibility to choose type of targets in moveAttack, fixes #2740