fix translation installation

I really don't get why, but it only works if I do it this way.
I thought that `translation.install` should make _() able to
fetch messages from anywhere in the program, but nothing was
translated in my tests except _() calls in inkstitch.py.

embroider.py

@@ -35,9 +35,7 @@ import networkx
 from pprint import pformat
 
 import inkstitch
-from inkstitch import cache, dbg, param, EmbroideryElement, get_nodes, SVG_POLYLINE_TAG, SVG_GROUP_TAG, PIXELS_PER_MM, get_viewbox_transform
-
-inkstitch.localize()
+from inkstitch import _, cache, dbg, param, EmbroideryElement, get_nodes, SVG_POLYLINE_TAG, SVG_GROUP_TAG, PIXELS_PER_MM, get_viewbox_transform
 
 class Fill(EmbroideryElement):
     def __init__(self, *args, **kwargs):

embroider_params.py

@@ -14,16 +14,13 @@ from wx.lib.scrolledpanel import ScrolledPanel
 from collections import defaultdict
 import inkex
 import inkstitch
-from inkstitch import Param, EmbroideryElement, get_nodes
+from inkstitch import _, Param, EmbroideryElement, get_nodes
 from embroider import Fill, AutoFill, Stroke, SatinColumn
 from functools import partial
 from itertools import groupby
 from embroider_simulate import EmbroiderySimulator
 
 
-inkstitch.localize()
-
-
 def presets_path():
     try:
         import appdirs

embroider_simulate.py

@@ -8,10 +8,7 @@ import colorsys
 
 import inkstitch
 from inkstitch import PIXELS_PER_MM
-from embroider import patches_to_stitches, get_elements, elements_to_patches
-
-
-inkstitch.localize()
+from embroider import _, patches_to_stitches, get_elements, elements_to_patches
 
 
 class EmbroiderySimulator(wx.Frame):

inkstitch.py

@@ -33,6 +33,8 @@ EMBROIDERABLE_TAGS = (SVG_PATH_TAG, SVG_POLYLINE_TAG)
 
 dbg = open("/tmp/embroider-debug.txt", "w")
 
+_ = lambda message: message
+
 # simplify use of lru_cache decorator
 def cache(*args, **kwargs):
     return lru_cache(maxsize=None)(*args, **kwargs)
@@ -47,7 +49,11 @@ def localize():
     locale_dir = os.path.join(locale_dir, 'locales')
 
     translation = gettext.translation("inkstitch", locale_dir, fallback=True)
-    translation.install()
+
+    global _
+    _ = translation.gettext
+
+localize()
 
 # cribbed from inkscape-silhouette
 def parse_length_with_units( str ):