Merge branch 'pull-1271' into develop

This is squashed version of six commits from PR that adds support for battery
status on cygwin platform.

Closes #1271

powerline/segments/common/bat.py

@@ -95,7 +95,7 @@ def _get_battery(pl):
 	else:
 		pl.debug('Not using pmset: executable not found')
 
-	if sys.platform.startswith('win'):
+	if sys.platform.startswith('win') or sys.platform == 'cygwin':
 		# From http://stackoverflow.com/a/21083571/273566, reworked
 		try:
 			from win32com.client import GetObject
@@ -116,9 +116,15 @@ def _get_battery(pl):
 
 					return _get_capacity
 				pl.debug('Not using win32com.client as no batteries were found')
-
-		from ctypes import Structure, c_byte, c_ulong, windll, byref
-
+		from ctypes import Structure, c_byte, c_ulong, byref
+		if sys.platform == 'cygwin':
+			pl.debug('Using cdll to communicate with kernel32 (Cygwin)')
+			from ctypes import cdll
+			library_loader = cdll
+		else:
+			pl.debug('Using windll to communicate with kernel32 (Windows)')
+			from ctypes import windll
+			library_loader = windll
 		class PowerClass(Structure):
 			_fields_ = [
 				('ACLineStatus', c_byte),
@@ -131,7 +137,7 @@ def _get_battery(pl):
 
 		def _get_capacity(pl):
 			powerclass = PowerClass()
-			result = windll.kernel32.GetSystemPowerStatus(byref(powerclass))
+			result = library_loader.kernel32.GetSystemPowerStatus(byref(powerclass))
 			# http://msdn.microsoft.com/en-us/library/windows/desktop/aa372693(v=vs.85).aspx
 			if result:
 				return None