Improve path resolution (command line compilation)

[FellippeHeitor]

QB64 info (please complete the following information):

• Latest stable, latest development.
• All systems.

Describe the bug
Calling QB64 from a different folder in the console still considers we're in QB64 folder and doesn't find relative paths.

To Reproduce
Steps to reproduce the behavior:

1. Launch Console
2. <path to qb64>/qb64 -x relative/path/to/bas/file

Expected behavior
Successful compilation.

[richardFK]

Once you have solved this (hopefully) will you also consider looking into issue #7 which seems to me to face a similar problem

Also I think my QB64 Discussion Topic

[dev build] Path issue reply #22

also is closely related to this issue. Just tested on dev f17c880 and when the QB64 folder is one level down - cannot find my ".\cinclude" and status message refers to ".\cinclude" (NOTE the two 's"). Github edit window shows two 's but when viewing the reply (as per other people) only ONE \ is displayed in the reply ???

Meanwhile stable build v1.5 correctly finds ".\cinclude" in its own folder.
The stable build v2.0 (folder _QB64) cannot find ".\include" from ANYWHERE (not even the stable build v1.5 folder(QB64).

[FellippeHeitor]

Noted.

[FellippeHeitor]

Also for $EXEICON.