Better label dialog editor. Libedit: now, cannot change the component name to an existing alias name (eeschema crashes when happens)

Code seriously cleaned, obscure and duplicated code removed, and some oddities removed.
Better support of multiline texts.

code cleanup, remove multiline text option in eeschema (multiline text is a work in progress) and minor enhancements

All: cleaning code to draw/plot texts (work in progress). Eeschema: italic and bold texts and labels allowed
(plot functions not yet updated for bold texts)

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+eeschema
        * commiting my changes to allow multiple instances of a given schematic file within 
a hierarchy:
        ** internally, m_currentScreen has been replaced with m_currentSheet,
                which is a list or 'path' of screens.  The path of screens is used to 
generate
                a series of timestamps, which is converted to flat component reference via 
a look-up
                table in the schematic files.
        ** this means that m_currentScreen is no longer used -- use GetScreen().
        ** GetScreen is virtual, as some of the dialogs keep around a WinEDA_BaseScreen 
pointer.
        ** all sub-sheets in a given schematic must have different names to generate a 
meaningful netlist.

set svn:eol-style property to native for all ascii files to support cross platform development