Fix various minor problems and update the documentation (#237)

These are minor fixes I've accumulated over time. The following
changes are somewhat notable:

- Added a missing entry for 'typeset -s' to the man page.
- Add strftime(3) to the 'see also' section. This and the date(1)
  addition are meant to add onto the documentation for 'printf %T'.
- Removed the man page the entry for ksh reading $PWD/.profile on
  login. That feature was removed in commit aa7713c2.
- Added date(1) to the 'see also' section of the man page.
- Note that the 'hash' command can be used instead of 'alias -t' to
  workaround one of the caveats listed in the man page.
- Use an 'out of memory' error message rather than 'out of space'
  when memory allocation fails.
- Replaced backticks with quotes in some places for consistency.
- Added missing documentation for the %P date format.
- Added missing documentation for the printf %Q and %p formats
  (backported from ksh2020: https://github.com/att/ast/pull/1032).
- The comments that show each builtin's options have been updated.

src/lib/libast/include/ast.h

@@ -176,7 +176,7 @@ typedef struct
 #define FMT_ALWAYS	0x01		/* always quote			*/
 #define FMT_ESCAPED	0x02		/* already escaped		*/
 #define FMT_SHELL	0x04		/* escape $ ` too		*/
-#define FMT_WIDE	0x08		/* don't escape 8 bit chars	*/
+#define FMT_WIDE	0x08		/* don't escape 8-bit chars	*/
 #define FMT_PARAM	0x10		/* disable FMT_SHELL ${$( quote	*/
 
 /*

src/lib/libast/include/glob.h

@@ -130,7 +130,7 @@ struct _glob_
 /* error return values */
 #define GLOB_ABORTED	1
 #define GLOB_NOMATCH	2
-#define GLOB_NOSPACE	3
+#define GLOB_NOSPACE	3	/* note: this error is for ENOMEM */
 #define GLOB_INTR	4
 #define GLOB_APPERR	5
 #define GLOB_NOSYS	6

src/lib/libast/include/ls.h

@@ -35,7 +35,7 @@
 #include <ast_mode.h>
 
 /*
- * some systems (could it beee AIX) pollute the std name space
+ * some systems (could be AIX) pollute the std name space
  */
 
 #undef	fileid

src/lib/libast/include/regex.h

@@ -118,7 +118,7 @@
 #define REG_EBRACE	9		/* \{...\} or {...} imbalance	*/
 #define REG_BADBR	10		/* invalid {...} digits		*/
 #define REG_ERANGE	11		/* invalid [...] range endpoint	*/
-#define REG_ESPACE	12		/* out of space			*/
+#define REG_ESPACE	12		/* out of memory		*/
 #define REG_BADRPT	13		/* unary op not preceded by re	*/
 #define REG_ENULL	14		/* empty subexpr in pattern	*/
 #define REG_ECOUNT	15		/* re component count overflow	*/