Further test updates after the dotted name 'import' change

Fixed quoted import names in replace.eel, stringcase.eel and stringquote.eel.

Added misplaced tree.eel test to test.eel.

Updated test-stripped-quoted.eel. Now includes all tests, and uses extension
.sqc for the test files, to avoid confusion with project .c source files.
'import' can now find local modules regardless of current directory

Added $.current_module_path, which holds the path to the module currently
being compiled, whenever available.

__load_via_path_modules() now tries $.current_module_path before going
through $.path_modules.

When no module is being compiled, $.current_module_path holds the path to
the first module compiled in the state; typically the main application
module. This allows runtime load() calls (which also serves as the backend
for 'import') to behave more reliably - though it should be noted that a
module imported from a subdirectory using load() will still get the path
of the main module; NOT the path of the module itself.

Closes #40.