Informing about process exit was not reliable

Unfortunatelly that didn't work right so for the moment I'm removing it
Document how ConqueVlad should be configured to enter/exit normal/insert mode

This is not yet fully implemented. It just helps me to clear up how
Conque should be configured.
Typo
Make the cursor positioning code easier for reading

Also the code now does not make any difference between 'normal' and
'edit' mode.
Allow adding lines to a buffer past it's end

When you enter normal mode and prepend some lines before current cursor
line, after return to insert mode it may try to write beyond buffer end.
This caused python exception and text disapeared. It is similar code to what is
used in __getitem__
Integrate support for s:ConqueTerm_InsertModeKey

Basically in 'normal' or 'edit' mode we don't limit keys functionality
now. Only if theres s:ConqueTerm_InsertModeKey specified, we watch this
key and switch back to insert mode.
Fix documetation index

I changed the order of paragraphs earliear and I forgot to update the
index
Synchronize the doc index with the text even more

This should be automated somehow ...
Make the <esc> key properly switch 'normal' and 'insert' mode

In line with the recent changes, call set_mappings("toggle") to switch
the Conque mode
One previous commits was missing inv_map_modifier definition
And make toggle key switch the buffer using set_mappings too
Do not remap special keys like g:ConqueTerm_EscKey

The keys are mapped in range 33-127. If y ou set g:ConqueTerm_EscKey
to, for example, '+', it's mapping would be overwritten here. So first
detect whether we should or should not map the key.

This is not the only place, earlier in the file there is range 1-31
which will need to be fixed too.
Unify of handling the <Bar> character

Previously there was separate if - endif paragraph, but it can be folded
into the same code as other characters.
Stop remapping g:ConqueTerm_* in range 1-31

Similar change as before, this time in range 1-31. It was necessary to
shift the mapping of g:ConqueTerm_ToggleKey before mapping the ranges so
that they are able to detect that they should not overwrite the mapping.

Also I added <silent> <buffer> to g:ConqueTerm_ToggleKey mapping.
Added the ability to mark paused terminals

It may be confusing whether you are in insert mode - typing on terminal,
or in isert mode modifying the buffer. This should ease the confusion.
Updated readme