gdb-ui problem

[Sun Yijiang]

When debug a large project, source files maybe in different
directories againt the executable.  gdb can point out where these
files locates, but gdb-ui simply find the source files under current
working directory, and if there is none, it will create one.  I think
this needs to be fixed, gdb-ui's behavior should be like ddd, who will
ask gdb for file paths it cannot find under current directory.  In
fact, I'm working on this feature.