Housekeeping: code reorg and build process redo (#87)

- Reorganized the con4m src and include directories to make them more sane (haven't gone IWYU though, just more sane on the file system)
- Retool the build process; the dev command now lets you switch profiles with 'dev profile' and passes any additional config options to meson. There are now MORE config options, including 'show_preprocessor_config' which dumps emits compiler warnings with the values of preproc config info.
- Fix the issue w/ CON4M_ROOT being necessary to run tests.
- Remove unnecessary alignment specs
- Remove depreciation warning.

.github/workflows/test.yml

@@ -77,8 +77,11 @@ jobs:
         if: runner.os == 'macOS'
         run: brew install meson ninja
 
+      - name: Setup
+        run: ./dev profile test
+
       - name: Build
-        run: ./dev testbuild
+        run: ./dev compile
 
       - name: Run
         run: ./dev run