Expand certain table sizes, add comments to Makefile.local

Expanded the globalsymbol string table size: from 1024 to 65536.

    Expanded the how often to reallocate string table is performed:
    from 100 to 1024.

    Expanded the number env_pool elements to allocate at a time:
    from 10 to 256.

    Improve comments on Makefile.local and add a few more examples
    of how it might be used.

CHANGES

@@ -8,6 +8,17 @@ The following are the changes from calc version 2.14.0.15 to date:
 
     Trimmed long line in the CONTRIBUTING.md file.
 
+    Expanded the globalsymbol string table size: from 1024 to 65536.
+
+    Expanded the how often to reallocate string table is performed:
+    from 100 to 1024.
+
+    Expanded the number env_pool elements to allocate at a time:
+    from 10 to 256.
+
+    Improve comments on Makefile.local and add a few more examples
+    of how it might be used.
+
 
 The following are the changes from calc version 2.14.0.14 to 2.14.0.14:
 

Makefile.local

@@ -8,11 +8,23 @@
 # To replace a Makefile variable, use := symbols.  For example:
 #
 #	CCWERR:= -Werror
-#
+
-# NOTE: You need to remove the leading '#<whitespaces>' to take effect.
+###################################################################
-# Comments start with a #-character.
+# NOTE: For this and other commended out examples in this file,	  #
-#
+# you need to remove the leading '#<whitespaces>' to take effect. #
+#								  #
+# Comments start with a #-character.				  #
+###################################################################
+
 # You can append to an existing Makefile variable using '+=' symbols.
 # For example:
 #
 #	CFLAGS+= -Ofast
+
+# For example, on macOS 12.1, you can use the following lines to
+# invoke clang's AddressSanitizer.  You do NOT want to do this by
+# by default!  Do this only if you are debugging calc using clang.
+#
+#	CFLAGS+= -fsanitize=address -fno-omit-frame-pointer
+#	LDFLAGS+= -fsanitize=address -fno-omit-frame-pointer
+#	CALC_ENV+= ASAN_OPTIONS=detect_stack_use_after_return=1

func.c

@@ -144,7 +144,7 @@ E_FUNC LIST* matindices(MATRIX *mp, long index);
 /*
  * malloced environment storage
  */
-#define ENV_POOL_CHUNK 10	/* env_pool elements to allocate at a time */
+#define ENV_POOL_CHUNK (1<8)	/* env_pool elements to allocate at a time */
 struct env_pool {
     char *getenv;	/* what getenv() would return, NULL => unused */
     char *putenv;	/* pointer given to putenv() */

str.c

@@ -41,8 +41,8 @@
 #include "banned.h"	/* include after system header <> includes */
 
 
-#define STR_TABLECHUNK	100	/* how often to reallocate string table */
+#define STR_TABLECHUNK	(1<<10)	/* how often to reallocate string table */
-#define STR_CHUNK	(1<<11)	/* size of string storage allocation */
+#define STR_CHUNK	(1<<16)	/* size of string storage allocation */
 #define OCTET_VALUES	256	/* number of different values in a OCTET */
 #define STR_UNIQUE	(1<<7)	/* size of string to allocate separately */