Code clarification about 3 confusing functions to display info: DisplayInfo (displaying a message info) and class members DisplayInfo and Display_Infos doing the same thing (see changelog)

Global variable unobfuscation, new library path search, and lots of other changes.  See CHANGELOG.txt.

Added: Zones unfill in polygon mode

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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