VFS: support for creating dirs

[Jan Wassenberg]

VFS requires a bit of work so it can create real directories when files are written to not-yet-existing dirs. This is needed for the XMB move, because they no longer reside in the game's data dirs that are sure to exist anyway.

[Jan Wassenberg]

(In [3874]) FILE_WRITE_TO_MOD is now FILE_WRITE_TO_TARGET ERR_(FILE|PATH)_NOT_FOUND -> ERR_TNODE_NOT_FOUND, ERR_NOT_(FILE|DIR) -> ERR_TNODE_WRONG TYPE path_util:

• path_append: bugfix (no more extraneous /); add support for appending slash
• path_replace: bugfix (no more warnings for expected error)
• add path_last_component, path_foreach_component
• move some defs to the header that belong there from vfs.h/path.h

file: add dir_create; move PosixFile definition here and provide accessor for fileio vfs: no longer automatically append slash; instead, make sure caller does vfs_mount:

• mount_realpath: bugfix (strip trailing /), interface improvement
• document write_target; clarify MULTIPLE_MOUNTINGS; add support for creating real dirs

vfs_tree:

• refactor TDir::add into find, add, find_and_add
• fix TDir and TNode for dir-ends-with-slash requirement
• split up lookup into lookup_cb and path_foreach_component
• add support for inserting dirs with given mount point: tree_add_path (needed when mounting)

wposix: get rid of weird PATH_MAX = 260 (Win32 weirdness)

TextureManager: remove no longer needed SupportedTextureFormats GameSetup, Xeromyces: setup XMB location to data/cache/mods/official/xmb Util: HardcodedErrorString now uses error_description_r VFSUtil, i18n: fixes for dir slash issue

Closes #79, #80

[(none)]

Milestone Playability Demo deleted