Log Message:
Update to openttd-data-0.5.2, provided by Leonardo Taccari in PR 50014.

Changes:

OpenGFX 0.5.2 (12 Apr 2015)
---------------------------
- Add: [Makefile] target 'bananas' (closes #6877, #6848)
- Fix: [Makefile] Add dependency generation for pnml->nml
- Fix: [Makefile] dependencies, esp. wrt. HG revision numbers getting compiled \ 
into files
- Fix: Alignment of GUI icons that have different sizes in 1x and 2x zoom
- Fix: 2x GUI sprite for purchase land was attached to the viewport sprite \ 
instead of to the GUI sprite (commit:ba02a90fab52) (issue FS#6267)
- Fix: Do not crop the default-window-size icon (issue FS#6258)

OpenGFX 0.5.2-RC1 (16 Feb 2015)
-------------------------------
- Add: 2x GUI zoom sprites
- Add: the all black ground sprites introduced in OpenTTD r26869
- Add: Translations for Africans, Italian, Latin and Lithuanian
- Update: Translation for English (US)
- Change:     [Makefile] Make sure that mercurial output is not changed by user \ 
presets
- Codechange: [Makefile] Simplify a few pointless programme definitions
- Fix:        [Makefile] No need to query the whereabouts of required programmes \ 
when we make no use of that anyway (issue #5759)

OpenGFX 0.5.1 (10 May 2014)
---------------------------
- Change/Fix (425e3a719210): [Makefile] Re-introduce target 'clean-gfx' and have \ 
'clean' remove the gimp script files (blathijs)
- Change: [Makefile] No point to bundle .hgtags .hgignore and .devzone files \ 
with source bundles
- Change: [Makefile] Use a temporary filename for custom_tags.txt and only \ 
update it, if the results would differ from the existing one
- Change: [Makefile] Cache custom_tags.txt and don't always re-build it
- Add: [Makefile] musa.ini for upload to bananas
- Fix (425e3a719210): [Makefile] Install into the baseset dir, not the NewGRF dir
- Fix (425e3a719210): create md5sum file for distribution and local check with \ 
the same rule (blathijs)
- Fix (425e3a719210): Reinstate the possibility to (not) install documentation \ 
and to choose a separate install dir for them
- Fix: [Makefile] Use the same variable name for changelog, readme and license \ 
files (blathijs)
- Fix 510292759967: [Makefile] Don't fail to build from fresh clones
- Fix afdd36f69c4c: [Makefile] Don't remove used scripts
- Fix: [Makefile] More woes with custom_tags.txt and installation (blathijs)
- Cleanup: Remove unused files from script dir
- Cleanup: Remove more unused files