Adjust clang-format settings

The main intent is to not allow enums to get condensed to a single line,
but this has the side effect of making clang-format stop attaching
braces to the start of the enum. I felt it made sense to use a different
brace style everywhere rather than live with just enums with braces on a
separate line.

.clang-format

@@ -4,6 +4,7 @@ AccessModifierOffset: -4
 AllowShortFunctionsOnASingleLine: Inline
 AllowShortIfStatementsOnASingleLine: false
 AllowShortLoopsOnASingleLine: false
+AllowShortEnumsOnASingleLine: false
 DerivePointerAlignment: false
 IncludeBlocks: Preserve
 IncludeCategories:
@@ -20,3 +21,4 @@ SpacesBeforeTrailingComments: 1
 Standard: Cpp11
 TabWidth: 4
 UseTab: AlignWithSpaces
+BreakBeforeBraces: Linux