Speeds up font compilation by around 200%

Cython is used to compile some hot paths into native Python extensions.
These hot paths were identified through running ufocompile with the hotshot
profiler and then converting file by file to Cython, starting with the "hottest"
paths and continuing until returns were deminishing. This means that only a few
Python files were converted to Cython.

Closes #23
Closes #20 (really this time)

init.sh

@@ -142,6 +142,35 @@ else
     ln -vfs ../../../misc/ttf2woff/ttf2woff "$VENV_DIR/bin"
   fi
 
+  has_newer() {
+    DIR=$1
+    REF_FILE=$2
+    for f in $(find "$DIR" -type f -name '*.pyx' -newer "$REF_FILE" -print -quit); do
+      return 0
+    done
+    return 1
+  }
+
+  check_cython_dep() {
+    DIR=$1
+    REF_FILE=$DIR/$2
+    set -e
+    if [ ! -f "$REF_FILE" ] || has_newer "$DIR" "$REF_FILE"; then
+      pushd "$DIR" >/dev/null
+      if [ -f requirements.txt ]; then
+        pip install -r requirements.txt
+      fi
+      python setup.py build_ext --inplace
+      popd >/dev/null
+    fi
+  }
+
+  # native booleanOperations module
+  check_cython_dep  misc/pylib/booleanOperations  flatten.so
+  check_cython_dep  misc/pylib/copy  copy.so
+  check_cython_dep  misc/pylib/fontbuild  mix.so
+  check_cython_dep  misc/pylib/robofab  glifLib.so
+
   # ————————————————————————————————————————————————————————————————————————————————————————————————
   # $BUILD_TMP_DIR
   # create and mount spare disk image needed on macOS to support case-sensitive filenames
@@ -179,10 +208,9 @@ else
       if $NEED_GENERATE; then
         break
       fi
-      for srcfile in $(find src/Interface-${style}.ufo -type f -newer "$GEN_MAKE_FILE"); do
+      if has_newer "src/Interface-${style}.ufo" "$GEN_MAKE_FILE"; then
         NEED_GENERATE=true
-        break
-      done
+      fi
     done
   fi