Fix small issue when panning with middle button.
Internal unit improvements and Pcbnew s-expression file format changes.

* Move EDA_TEXT object into separate header and source file.
* Compile EDA_TEXT class separately for BOARD_ITEM and SCH_ITEM units.
* Compile PAGE_INFO  class separately for BOARD_ITEM and SCH_ITEM units.
* Minor formatting tweaks to Pcbnew s-expression file.
* Move internal unit formatting functions into BOARD_ITEM and SCH_ITEM.
Eeschema: BOM list generation: some fixes and enhancements.
drawframe.cpp: commit a fix about scrollbars  from lajos kamocsay
More internal unit improvements.

* Move all convert from internal to user units functions into separate file.
* Remove internal units parameter from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Compile these conversion routines separately for the appropriate pcb or
  schematic internal units.
* Move internal units specific status bar update code into the appropriate
  application for updating the status bar.
* Move millimeter user units rounding function to common.cpp.
Commit patch fixing an issue in pan with middle mouse button (from lajos kamocsay)
Other minor fixes.
Pcbnew nanometer internal unit fixes.

* Scale page reference border and title block, grid sizes, and zoom factors
  correctly for nanometers.
work on footprint plugin API
Fix a serious bug in EDA_RECT::Intersects
Kicad manager: code cleaning. Dead code removed and minor fixes. support of new .kicad_brd extension.
More internal unit improvements.

* Move all convert from user to internal units into base_units.cpp.
* Remove internal units parameters from all moved conversion functions.
* Revise all source code that calls the moved conversion functions.
* Remove internal units from all dialog text control helper classes.
Removal of internal units.

* Remove internal units from BASE_SCREEN and it's derivatives.
* Remove internal units from EDA_DRAW_FRAME and it's derivatives.
* Use build time code to replace internal units conversions.
* Fix scaling bug in page layout sample window that I created in my
  last commit.
more footprint support for LEGACY_PLUGIN
cvpcb LEGACY_PLUGIN usage factoring
LEGACY_PLUGIN is now in full use:
*) for footprint access into *.mod files and 
*) BOARD save/load

The item_io.cpp and ioascii.cpp have been set off to the side for reference
as *.notused, for awhile.

The CMake options USE_NEW_PCBNEW_LOAD and USE_NEW_PCBNEW_SAVE are gone,
this is now the mandatory usage of the LEGACY_PLUGIN.  This should reduce
code maintenance for awhile until the s-expression plugin comes into 
play.  But at least for legacy format, there is not two code bodies
to maintain any more.

A new LEGACY_PLUGIN footprint library caching scheme is in place which 
needs some testing.  It should not be any faster, but might give better 
results in a networked environment if there is *.mod files on the server.
touch ups
uncrustify math_for_graphics, add copyright legacy_plugin.h
PLUGIN API Doxygen comments
Make Gerbview working with USE_PCBNEW_NANOMETRES option ON
use a block scope to invoke wxFFile's destructor before renaming temporary file
// Dick Hollenbeck's KiROUND R&D
// This provides better project control over rounding to int from double
// than wxRound() did.  This scheme provides better logging in Debug builds
// and it provides for compile time calculation of constants.


#include <stdio.h>
#include <assert.h>
#include <limits.h>

//-----<KiROUND KIT>------------------------------------------------------------

/**
 * KiROUND
 * rounds a floating point number to an int using
 * "round halfway cases away from zero".
 * In Debug build an assert fires if will not fit into an int.
 */

#if defined( DEBUG )

// DEBUG: a macro to capture line and file, then calls this inline

static inline int KiRound( double v, int line, const char* filename )
{
    v = v < 0 ? v - 0.5 : v + 0.5;
    if( v > INT_MAX + 0.5 )
    {
        printf( "%s: in file %s on line %d, val: %.16g too ' > 0 ' for int\n", __FUNCTION__, filename, line, v );
    }
    else if( v < INT_MIN - 0.5 )
    {
        printf( "%s: in file %s on line %d, val: %.16g too ' < 0 ' for int\n", __FUNCTION__, filename, line, v );
    }
    return int( v );
}

#define KiROUND( v )    KiRound( v, __LINE__, __FILE__ )

#else

// RELEASE: a macro so compile can pre-compute constants.

#define KiROUND( v )  int( (v) < 0 ? (v) - 0.5 : (v) + 0.5 )

#endif


//-----</KiROUND KIT>-----------------------------------------------------------

// Only a macro is compile time calculated, an inline function causes a static constructor
// in a situation like this.
// Therefore the Release build is best done with a MACRO not an inline function.
int Computed = KiROUND( 14.3 * 8 );


int main( int argc, char** argv )
{
    for( double d = double(INT_MAX)-1;  d < double(INT_MAX)+8;  d += 2.0 )
    {
        int i = KiROUND( d );

        printf( "t: %d  %.16g\n", i, d );
    }

    return 0;
}
missing include