Use canonical format for MSVS project/solution files

Use the same format as is used by MSVS itself to avoid spurious changes when
modifying the files. Notably:

- Use DOS end of line format (0D 0A).
- Add UTF-8 BOM (EF BB BF) to the beginning of the files.
- Do not put CR LF at the end of the last line in the file.

Closes https://github.com/wxWidgets/wxWidgets/pull/440

utils/screenshotgen/src/screenshotgen_vc7.sln

@@ -1,3 +1,4 @@
+
 Microsoft Visual Studio Solution File, Format Version 8.00
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "screenshotgen", "screenshotgen_vc7.vcproj", "{65A1C4C8-E1D5-5972-8550-0F5631031FBB}"
 EndProject

utils/screenshotgen/src/screenshotgen_vc8.sln

@@ -1,3 +1,4 @@
+
 Microsoft Visual Studio Solution File, Format Version 9.00
 # Visual Studio 2005
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "screenshotgen", "screenshotgen_vc8.vcproj", "{D36F115C-330D-5EAE-B66F-885D6BE20540}"

utils/screenshotgen/src/screenshotgen_vc9.sln

@@ -1,3 +1,4 @@
+
 Microsoft Visual Studio Solution File, Format Version 10.00
 # Visual Studio 2008
 Project("{8BC9CEB8-8B4A-11D0-8D11-00A0C91BC942}") = "screenshotgen", "screenshotgen_vc9.vcproj", "{820F5E3E-095B-580D-AE31-7E492C647B90}"