Enhance the Spanish translation

Correct terminology, styling, casing and fix some typos.
Merge pull request #407 from Swyter/patch-2

Enhance the Spanish translation
Update es_ES.ini

Added new strings for backend and error message. Minor typos. Shorter string to fit screen properly in some cases (android devices with low resolution, using portrait mode or 1x screen size in Windows).
Merge pull request #408 from ppmeis/patch-58

Update es_ES.ini
[Reporting] added

https://github.com/hrydgard/ppsspp/commit/7d44711198867f27fbd98820727702eeba823625
[Reporting] added

https://github.com/hrydgard/ppsspp/commit/7d44711198867f27fbd98820727702eeba823625
Update es_ES.ini

Added Reporting section.
Update es_ES.ini

Fix typo.
Merge pull request #409 from ppmeis/patch-59

Update es_ES.ini
Cosmetic fix
Add Bulgarian, contributed by "+"
Update cz_CZ.ini
Update cz_CZ.ini
Merge pull request #410 from Tsbook/master

Update cz_CZ.ini
Update zh_TW.ini [Reporting]
Update zh_CN.ini [Reporting]
Update zh_CN and TW
Minor cosmetic fix
Add a string
Update zh_CN and tw (7-zip)