Align with other scanners to use 1-query db_file_ping_bypath(). Also refactor to
reduce indent level and fix memleak of mfi->album + mfi->album_artist.
Thanks to Denis Denisov and cppcheck for notifying about the below. The leaks
are edge cases, but the warning of dereference of avail in alsa.c points at
a bug that could probably cause actual crashes.
[src/evrtsp/rtsp.c:1352]: (warning) Assignment of function parameter has no effect outside the function. Did you forget dereferencing it?
[src/httpd_daap.c:228]: (error) Memory leak: s
[src/library.c:280]: (warning) %d in format string (no. 2) requires 'int' but the argument type is 'unsigned int'.
[src/library.c:284]: (warning) %d in format string (no. 2) requires 'int' but the argument type is 'unsigned int'.
[src/library/filescanner_playlist.c:251]: (error) Resource leak: fp
[src/library/filescanner_playlist.c:273]: (error) Resource leak: fp
[src/outputs/alsa.c:143]: (warning) Assignment of function parameter has no effect outside the function. Did you forget dereferencing it?
[src/outputs/alsa.c:657]: (warning) Possible null pointer dereference: avail
[src/outputs/dummy.c:75]: (warning) Assignment of function parameter has no effect outside the function. Did you forget dereferencing it?
[src/outputs/fifo.c:245]: (warning) Assignment of function parameter has no effect outside the function. Did you forget dereferencing it?
[src/outputs/raop.c:1806]: (warning) Assignment of function parameter has no effect outside the function. Did you forget dereferencing it?
[src/outputs/raop.c:1371]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/outputs/raop.c:1471]: (warning) %u in format string (no. 1) requires 'unsigned int' but the argument type is 'signed int'.
[src/outputs/raop_verification.c:705] -> [src/outputs/raop_verification.c:667]: (warning) Either the condition 'if(len_M)' is redundant or there is possible null pointer dereference: len_M.
Setting the response headers "Cache-Control" and "Last-Modified" results
in clients being able to cache the response. For a subsequent request
for the same file, the browser sets the request header
"If-Modified-Since" with the value from "Last-Modified" from the last
response. The server (httpd.c) checks if the file has been modified and
if not returns HTTP 304 Not Modified.
the admin password
Changes the default for the admin password to be unset, by default only
allowing access to the WEB_ROOT files if accessed from localhost.
Avoids the need to have definition of dmap_find_field in dmap_common.h that
must be kept in sync with the definition that gperf generates.
Also should fix compilation problems when gperf is not present, ref pr #390
