[Lazarus] Different paths, different computers, and one project

[Marcos Douglas B. Santos]

Imagine a project that works only with set of unit paths (-Fu), not packages.
The issue is that a computer could have a different path for a lib,
comparing to another one.

I've removed the paths from the project (.lpi) and added an
`@extrafpc.cfg` with `-Fu` and `-Fl` paths. I can compile the project,
but the code-completion doesn't work because the IDE can't find the
units.
I can't also use `Other sources` option cause it will have the same
problem using `-Fu` and hard-coded paths.

How to configure the paths?

Regards,
Marcos Douglas