Make sure TARGET is set correctly when CURDIR contains spaces.

With this fix the `TARGET` variable is set correctly when the project directory
(or its path) contains spaces. So in this case:

    /Users/Joe/Dropbox (Personal)/example project

`TARGET` will be set to `example_project` instead of `Dropbox example project`
(like it was before this fix).

Arduino.mk

@@ -266,7 +266,9 @@ endif
 # Default TARGET to pwd (ex Daniele Vergini)
 
 ifndef TARGET
-    TARGET  = $(notdir $(CURDIR))
+    space :=
+    space +=
+    TARGET = $(notdir $(subst $(space),_,$(CURDIR)))
 endif
 
 ########################################################################

HISTORY.md

@@ -17,6 +17,7 @@ I tried to give credit whenever possible. If I have missed anyone, kindly add it
 - Tweak: Added some more Continuous Integration tests (https://github.com/sej7278)
 - Tweak: Updated Fedora instructions (https://github.com/sej7278)
 - Fix: Preserve original extension for object files, support asm sources in core, fixes pulseInASM (Issue #255, #364) (https://github.com/sej7278)
+- Fix: Make sure TARGET is set correctly when CURDIR contains spaces.
 
 ### 1.5 (2015-04-07)
 - New: Add support for new 1.5.x library layout (Issue #275) (https://github.com/lukasz-e)