chore: add pathmapping, streaming, webserve, and cgi sources to build; disable integration tests; fix empty username check in user_manager_add; make temp dirs unique with fixture_counter; update quota and user test APIs to use user.id and cast quota_bytes

tests/fixtures/fixtures.c

@@ -8,8 +8,10 @@
 #include <dirent.h>
 #include <time.h>
 
+static int fixture_counter = 0;
+
 int fixture_create_temp_dir(char *path, size_t size) {
-    snprintf(path, size, "/tmp/nwedav_test_%d_%ld", getpid(), (long)time(NULL));
+    snprintf(path, size, "/tmp/nwedav_test_%d_%ld_%d", getpid(), (long)time(NULL), fixture_counter++);
     return mkdir(path, 0755);
 }