[Add] Give errors on unsupported OS code.

src/lfile.c

@@ -22,6 +22,8 @@ char* lfile_basePath(void) {
   if(lephisto_base[0] == '\0') {
 #ifdef LINUX
     home = getenv("HOME");
+#else
+#error "Needs implentation."
 #endif
     snprintf(lephisto_base, PATH_MAX, "%s/.lephisto/", home);
   }
@@ -49,6 +51,8 @@ int lfile_dirMakeExist(char* path) {
       WARN("Dir '%s' does not exist and unable to create", path);
       return -1;
     }
+#else
+#error "Needs implentation."
 #endif
 
   return 0;
@@ -75,6 +79,8 @@ int lfile_fileExists(char* path, ...) {
 
   if(stat(file, &buf)==0) /* Stat worked, file must exist. */
     return 1;
+#else
+#error "Needs implementation."
 #endif
   return 0;
 }
@@ -117,6 +123,8 @@ char** lfile_readDir(int* lfiles, char* path) {
   }
 
   closedir(d);
+#else
+#error "Needs implementation."
 #endif
 
   /* What if we find nothing? */