Spanish translation

Added Spanish translation for all existing values.
add transparent icon to fix compiling errors

packages/apps/PDroidManager/src/net/digitalfeed/pdroidalternative/ApplicationsDatabaseFillerTask.java:225: cannot find symbol
symbol  : variable raw
location: class net.digitalfeed.pdroidalternative.R
    				        blankIcon = IconHelper.getByteArray(context.getResources().openRawResource(R.raw.blank));
    				                                                                                    ^
packages/apps/PDroidManager/src/net/digitalfeed/pdroidalternative/ApplicationsDatabaseFillerTask.java:231: cannot find symbol
symbol  : variable raw
location: class net.digitalfeed.pdroidalternative.R
                        blankIcon = IconHelper.getByteArray(context.getResources().openRawResource(R.raw.blank));
                                                                                                    ^
Update 'blank.png' file to be a 1x1 blank PNG (thanks TamCore for observing that this file was missing).
Merge branch 'master' of https://github.com/alceasan/pdroid-manager
Remove non-translatable strings from Spanish translation.
Update credits to include alceasan as the translator for Spanish
Update version number
Update API support to include Android 4.2.1