This may help address issues where people forget to read the documentation,
don't run "git submodule update", and end up with a df-structures version
that's too old (which is somewhat common, it turns out).
This was previously done right before SC_VIEWSCREEN_CHANGED events
were handled, meaning that code handling earlier events that used
top_viewscreen (rather than getCurViewscreen()) could refer to an
invalid viewscreen, i.e. in the tick after it was deleted.
Fixes#747
* Several fatal errors that occurred during core initialization didn't
stop initialization or set 'errorstate' properly, which caused
update hooks and other code to crash later. This has been fixed and
should address crashes like the one mentioned in #470.
* Errors when loading dfhack.lua now cause Lua::Open() to fail, which
triggers a fatal error in Core::Init()
* Failure to initialize the console no longer results in a call to
fatal() (since it didn't actually stop initialization previously)
cur_savegame.save_dir can be populated when the save directory does
not yet exist after world generation (since the game can be aborted
at that stage without saving).
* GCC does not allow std::string instances or enums without a base
type to be passed as varargs
* Fixed path concatenation issue causing dfhack.init to not be loaded
* load/unload/reload are no longer restricted to plugins that exist
on startup
* Names passed to DFHACK_PLUGIN must match the plugin's filename
(remotefortressreader vs RemoteFortressReader, counters vs probe)
* "plug" output lists all plugins and state/command information
* Deleted plugins can be reloaded again if they are replaced
* load/unload/reload don't fail silently with broken plugins
* Built-in commands are recognized internally (e.g. "help help"
does not display "help is not a recognized command"), although help
for them is not yet implemented
* New command: "type" (bash-like) - shows where/how a command is
implemented
* "plug" can accept multiple plugin names
* "ls" displays more information about unloaded/unrecognized plugins
* "load all" changed to "load -all" (or "load --all", "load -a", ...)