Update Windows Build

Fix the issues with cx_Freeze builds on newer versions of python and
with newer version of PyQt5
- Update .gitignore to ignore .spec files
- Update package.py to use pyInstaller instead of cx_Freeze
- Update requirements-windows to have pyInstaller instead of cx_Freeze
- Update setup.nsi to work with build and packaging changes
- Add win_version_info.temp to build a version information file for
  pyInstaller as part of the package.py script

win_version_info.temp

@@ -0,0 +1,43 @@
+# UTF-8
+#
+# For more details about fixed file info 'ffi' see:
+# http://msdn.microsoft.com/en-us/library/ms646997.aspx
+VSVersionInfo(
+  ffi=FixedFileInfo(
+    # filevers and prodvers should be always a tuple with four items: (1, 2, 3, 4)
+    # Set not needed items to zero 0.
+    filevers=({0}, {1}, {2}, 0),
+    prodvers=({0}, {1}, {2}, 0),
+    # Contains a bitmask that specifies the valid bits 'flags'r
+    mask=0x3f,
+    # Contains a bitmask that specifies the Boolean attributes of the file.
+    flags=0x0,
+    # The operating system for which this file was designed.
+    # 0x4 - NT and there is no need to change it.
+    OS=0x40004,
+    # The general type of file.
+    # 0x1 - the file is an application.
+    fileType=0x1,
+    # The function of the file.
+    # 0x0 - the function is not defined for this fileType
+    subtype=0x0,
+    # Creation date and time stamp.
+    date=(0, 0)
+    ),
+  kids=[
+    StringFileInfo(
+      [
+      StringTable(
+        u'040904B0',
+        [StringStruct(u'CompanyName', u'Hardcoded Software'),
+        StringStruct(u'FileDescription', u'dupeGuru is a tool to find duplicate files on your computer.'),
+        StringStruct(u'FileVersion', u'{0}.{1}.{2}.0'),
+        StringStruct(u'InternalName', u'dupeGuru'),
+        StringStruct(u'LegalCopyright', u'© Hardcoded Software'),
+        StringStruct(u'OriginalFilename', u'dupeguru-win{3}.exe'),
+        StringStruct(u'ProductName', u'dupeGuru'),
+        StringStruct(u'ProductVersion', u'{0}.{1}.{2}.0')])
+      ]), 
+    VarFileInfo([VarStruct(u'Translation', [1033, 1200])])
+  ]
+)