a couple (relatively) low cost improvements

[dizergin]

1. If you got GLOBAL folder settings (it doesnt work properly at present!!!) it is quite naturally  to have possibility to set library files GLOBALLY( For the Linker itself  is not  intellegent to pick correct lib-file from the pointed folders). Now we got some inconsistance in the interface
2. Please set so-called flag (read-only) input fields (like  "Command line options (CCFLAGS)") in inactive state  - current behavior is rather confusing (for novices)