improvement: to prepare feature 1051, the code to add a single file (works for
the 3 picture types, ie thumb/file/high) has been factorized into a single
add_file function.
bug fixed: when a function not directly called by the API (such as merge_chunks
or the new add_file function) returning a PwgError, it was not stopping the
execution, it just sets the error code/message. Now we don't return PwgError,
we only create one and then exit().
git-svn-id: http://piwigo.org/svn/trunk@4346 68402e56-0260-453c-a942-63ccdbb3a9ee
7ee33e9c0c