Bug#23865 mysql-test-run.pl on Windows only supports debug and release configurations

Visual Studio builds each configuration in a different sub-directory.  Only the sub-
directories for release and debug are currently searched.


mysql-test/lib/mtr_misc.pl:
  Bug#23865 mysql-test-run.pl on Windows only supports debug and release configurations
  - Added usage comments.
mysql-test/mysql-test-run.pl:
  Bug#23865 mysql-test-run.pl on Windows only supports debug and release configurations
  - Moved Initial_Setup function to the command_line_setup function.
  - Defined new argument vs-config which can be used to inidicate the VS Configuration
  used to create the test executables. Argument can also be controlled with
  MTR_VS_CONFIG environment variable.

mysql-test/lib/mtr_misc.pl

@@ -66,6 +66,9 @@ sub mtr_add_arg ($$@) {
 
 ##############################################################################
 
+# Note - More specific paths should be given before less specific.  For examle
+# /client/debug should be listed before /client
+
 sub mtr_path_exists (@) {
   foreach my $path ( @_ )
   {
@@ -81,6 +84,9 @@ sub mtr_path_exists (@) {
   }
 }
 
+# Note - More specific paths should be given before less specific.  For examle
+# /client/debug should be listed before /client
+
 sub mtr_script_exists (@) {
   foreach my $path ( @_ )
   {
@@ -103,6 +109,9 @@ sub mtr_script_exists (@) {
   }
 }
 
+# Note - More specific paths should be given before less specific.  For examle
+# /client/debug should be listed before /client
+
 sub mtr_file_exists (@) {
   foreach my $path ( @_ )
   {
@@ -111,6 +120,9 @@ sub mtr_file_exists (@) {
   return "";
 }
 
+# Note - More specific paths should be given before less specific.  For examle
+# /client/debug should be listed before /client
+
 sub mtr_exe_maybe_exists (@) {
   my @path= @_;
 
@@ -129,6 +141,9 @@ sub mtr_exe_maybe_exists (@) {
   return "";
 }
 
+# Note - More specific paths should be given before less specific.  For examle
+# /client/debug should be listed before /client
+
 sub mtr_exe_exists (@) {
   my @path= @_;
   if (my $path= mtr_exe_maybe_exists(@path))