rename E__COUNT to ECOUNT

Rename the #define E__COUNT to ECOUNT to avoid confusion
with "E_STRING" error symbols.

Improve formatting of help/error, help/errno, and help/strerror.

Update .gitignore.

.gitignore

@@ -23,6 +23,8 @@ core*
 .dynamic
 .hsrc
 .static
+Makefile.our
+NOTES
 align32
 align32.h
 args.h
@@ -40,12 +42,12 @@ conf.h
 const_tmp
 cscript/.all
 cscript/4dsphere
+cscript/README
 cscript/fproduct
 cscript/mersenne
 cscript/piforever
 cscript/plus
 cscript/powerterm
-cscript/README
 cscript/simple
 cscript/square
 custom/.all
@@ -118,6 +120,8 @@ have_ustat
 have_ustat.h
 have_varvs
 help/.all
+help/COPYING
+help/COPYING-LGPL
 help/binding
 help/bindings
 help/bug
@@ -127,8 +131,6 @@ help/change
 help/changes
 help/contrib
 help/copy
-help/COPYING
-help/COPYING-LGPL
 help/cscript
 help/custom_cal
 help/errorcode
@@ -150,8 +152,6 @@ libcalc.*
 libcustcalc.*
 longbits
 longbits.h
-Makefile.our
-NOTES
 outfile
 sample_many
 sample_many-static
@@ -160,5 +160,6 @@ sample_rand-static
 status.chk_c.h
 tags
 terminal.h
+unused_tmp
 ver_calc
 win32/