Add clang-format configuration, clean up

.clang-format

@@ -0,0 +1,27 @@
+# clang-format is fairly limited, and these rules are approximate:
+#  - array initializers can get terribly mangled with clang-format 12.0,
+#  - sometimes it still aligns with space characters,
+#  - struct name NL { NL ... NL } NL name; is unachievable.
+BasedOnStyle: GNU
+ColumnLimit: 80
+IndentWidth: 4
+TabWidth: 4
+UseTab: ForContinuationAndIndentation
+BreakBeforeBraces: Allman
+SpaceAfterCStyleCast: true
+AlignAfterOpenBracket: DontAlign
+AlignOperands: DontAlign
+AlignConsecutiveMacros: Consecutive
+AllowAllArgumentsOnNextLine: false
+AllowAllParametersOfDeclarationOnNextLine: false
+IndentGotoLabels: false
+
+# IncludeCategories has some potential, but it may also break the build.
+# Note that the documentation says the value should be "Never".
+SortIncludes: false
+
+# This is a compromise, it generally works out aesthetically better.
+BinPackArguments: false
+
+# Unfortunately, this can't be told to align to column 40 or so.
+SpacesBeforeTrailingComments: 2

termo.c

@@ -1856,4 +1856,3 @@ termo_keycmp (termo_t *tk,
 	}
 	return key1.modifiers - key2.modifiers;
 }
-

tests/06buffer.c

@@ -2,7 +2,8 @@
 #include "../termo.h"
 #include "taplib.h"
 
-int main (int argc, char *argv[])
+int
+main (int argc, char *argv[])
 {
 	termo_t *tk;
 	termo_key_t key;

tests/31position.c

@@ -1,7 +1,8 @@
 #include "../termo.h"
 #include "taplib.h"
 
-int main (int argc, char *argv[])
+int
+main (int argc, char *argv[])
 {
 	termo_t *tk;
 	termo_key_t key;