Previously packaging completes successfully without any error
or warning.
With the fix, an error will be reported if write fails. It may
appear as "Cannot close file error" as we use threaded IO, which
could delay the error reporting until Close() call, so the user
of the File API needs to make sure Close() returns successfully.
Also fixed a deadlock in threaded_io_file if internal_file->Write
fails.
Fixes#160
Change-Id: I17f945150fb4021d2dcdbe784e557673f53ca583
ImportantFileWriter::WriteFileAtomically uses mkstemp internally,
which set file permission to 0600, which is not what we want.
Update the code to not use mkstemp instead.
Also updated temporary file name logic to include process id in
the name so it can be unique across processes.
Fixes#259
Change-Id: I2d5a375925cf552bc0db5269f409d7522e63fca5
KongQun Yang