MXS-2208 Move trim-functions from maxscale to maxbase

log.h now includes string.hh, which is conceptually wrong, but
log.h will shortly disappear and be superceded by log.hh.

query_classifier/qc_mysqlembedded/qc_mysqlembedded.cc

@@ -2854,7 +2854,7 @@ static void update_field_infos(parsing_info_t* pi,
 
             char func_name[strlen(f) + 3 + 1];      // strlen(substring) - strlen(substr) from below.
             strcpy(func_name, f);
-            trim(func_name);    // Sometimes the embedded parser leaves leading and trailing whitespace.
+            mxb::trim(func_name);    // Sometimes the embedded parser leaves leading and trailing whitespace.
 
             // Non native functions are surrounded by back-ticks, let's remove them.
             remove_surrounding_back_ticks(func_name);

query_classifier/qc_sqlite/qc_sqlite.cc

@@ -4445,8 +4445,8 @@ static bool get_key_and_value(char* arg, const char** pkey, const char** pvalue)
     {
         *p = 0;
 
-        *pkey = trim(arg);
-        *pvalue = trim(p + 1);
+        *pkey = mxb::trim(arg);
+        *pvalue = mxb::trim(p + 1);
     }
 
     return p != NULL;