Indent model.
============

IndentFlag regulates inenting in the engine.
Empty IndentFlag value disables indenting.
Default value is IndentFlag = CRLF & "  "
Value can be reset in line 
indent=<IndnetFlagValue>
in schema sml-header.
(or ? in source sml-header)


Indenting done with "saving text size" functionality:
any 7 continuous characters are replaced with tab.

Microbug:
 Therefore, this is assumed that browsers tab is
 7 characters which may be wrong.

Details.
========

In code,final indenting done
  in sub makei(d) in module funct.inc
Empty IndentFlage disables indenting.
Initial value of IndentFlag 
  a. default and first modification of 
     IndentFlag done in 
     function parse_s_ml_header( _
             start,hso,take_defaults) in cshema.inc
  b. second modification may be done in
     the same function when called from 
     source parser:
        compile_source(not (proceed_result_file and  proceed)) from manage_core.inc
        which calls:
        i = parse_s_ml_header(1,source,false) from compile.inc