The transform function now accepts a vector of filenames.

Only the first one is evaluated though. So it is no difference to before.
Define the prototypes of the test in a separate header file.
Changed structure of the test lib.

We call the lib now simplelib and the first
source code func1.c
Introduced second set of files that we try to transform.

Obviously, this doesn't work yet.
Display the number of tracked global functions.
A TextEdit will now contain the name of the affected file.

We use it to skip text edits that don't affect the main file. This is only
a temporarily solution. Usually, we would like to make the replacements in
the header file as well.
Renamed TrUnit to FilenameWithContents.

A Translation unit is more complex.
Fixed intend.
No longer skips non-main file related Textedit, just don't execute them.

We eventually need to execute them, so we should record them.
Added empty process_single_source_file() function.
Moved the code to load the actual source into the constructor.

Also renamed tr_unit variable to file as we are dealing with
a single file as it is for now.