Debugger: Add 'command[s]' to breakpoints, polish BP dialogs.

Add commands (CDB, gdb with '\n' delimiter for multiple),
rearrange dialogs, make ignore count a spin box.

src/plugins/debugger/breakpoint.h

@@ -100,6 +100,7 @@ public:
     int threadSpec;          // Thread specification.
     QString functionName;
     QString module;          // module for file name
+    QString command;         // command to execute
     bool tracepoint;
 };