[gtkmm] .clang-format: Improvements from Kjell.

[Murray Cumming <murrayc src gnome org>]

commit 3cc1b83438ff39d0802d8bdeb4175b664d02c178
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Feb 25 13:40:39 2016 +0100

    .clang-format: Improvements from Kjell.

 .clang-format |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)
---
diff --git a/.clang-format b/.clang-format
index 0f1ad0d..8d3b34c 100644
--- a/.clang-format
+++ b/.clang-format
@@ -1,7 +1,12 @@
 BasedOnStyle: Mozilla
-AlignAfterOpenBracket: false
 Standard: Cpp11
+AlignAfterOpenBracket: false
+AlignEscapedNewlinesLeft: true
+AlwaysBreakAfterDefinitionReturnType: None
 BreakBeforeBraces: Allman
-SpaceBeforeParens: Never
-
+BreakConstructorInitializersBeforeComma: false
+ColumnLimit: 100
+ConstructorInitializerAllOnOneLineOrOnePerLine: true
+ConstructorInitializerIndentWidth: 0
+IndentCaseLabels: false