Fix some doxygen warnings and errors

Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

src/git/fileops.h

@@ -4,7 +4,7 @@
 /**
  * @file git/fileops.h
  * @brief Git platform agnostic filesystem operations
- * @defgroup Git gitfiles
+ * @defgroup git_fileops Git filesystem operations
  * @ingroup Git
  * @{
  */
@@ -12,7 +12,7 @@
 #include "common.h"
 GIT_BEGIN_DECL
 /**
- * For each directory entry (except . and ..), run the function
+ * For each directory entry (except "." and ".."), run the function
  * "fn", passing it "arg" as its first argument and the path to
  * the entry as the second argument.
  * @param dir The directory to walk

src/git/oid.h

@@ -51,7 +51,7 @@ GIT_INLINE(void) git_oid_mkraw(git_oid *out, const unsigned char *raw)
  * @param str output hex string; must be pointing at the start of
  *        the hex sequence and have at least the number of bytes
  *        needed for an oid encoded in hex (40 bytes).  Only the
- *        oid digits are written; a '\0' terminator must be added
+ *        oid digits are written; a '\\0' terminator must be added
  *        by the caller if it is required.
  * @param oid oid structure to format.
  */
@@ -66,7 +66,7 @@ GIT_EXTERN(void) git_oid_fmt(char *str, const git_oid *oid);
  * @param str output hex string; must be pointing at the start of
  *        the hex sequence and have at least the number of bytes
  *        needed for an oid encoded in hex (41 bytes).  Only the
- *        oid digits are written; a '\0' terminator must be added
+ *        oid digits are written; a '\\0' terminator must be added
  *        by the caller if it is required.
  * @param oid oid structure to format.
  */