Pcbnew: fix bug in pcb_parser: incorrect pad local solder paste margin ratio value read when not 0. ( This also fixes bug 1170535 )

The internal BOM generator has bugs. I designed an XSL script, which converts the generated XML Partlist into
a CSV file for Libre Office or Open Office.  It is very easy to use. You can specify it as a plugin for 
Eeshema netlist generator.

It searches for all field names, generates the table headings accounting for all fields found in any part.
Then stuffs all the parts rows according to proper fields.

Eeschema: fix bug #1168116. Netlist generation: remove  dead code and fully outdated option pspice "use net number"
Pcbnew: layer manager: display tooltips using translated form (where internationalized, but always shown in English).

Changed format specifiers of some printf involved with size_t values to %zu to avoid runtime assertions.

Depending on build options seems that wx uses different types for size() so the Format string was not always correct. Put a fat warning in a comment too.

use lower case library names in *.pro & *.sch files, to match actual filenames in the template file set. Noticed on linux.

Also removed EDA_DRAW_FRAME::OnGrid which was totally dead (empty and unused)

Pcbnew: load footprint from modview: Because modview allows user to choose the footprint library, the selected library is forced when the footprint is loaded.
I am not sure this is 100% better, but this new behavior has some advantages, mainly in the footprint editor (you can load a footprint outside the selected library)

pcb_calculator: fix bug Bug #1167345

Slightly retuned for compensating the new position.

Fixed layer picker for exporting to pcbnew
Realigned pcb layer name with class BOARD

Dynamic contrast for netname and pin numbers ('halo' text)
Handle netname drawing even on diagonal tracks

More layer classification cleanup

bit string version of property_tree. The ram resident structure of the ptree is
mostly compatible with one created using the xml_parser from
boost::property_tree, with slight differences in the way atoms are stored. The
result is you can use Format() to convert from xml to s-expression, but not the
other way around. You can write a simple s-expression beautifier in just a few
lines of code.

The main value however is the s-expression parser, i.e. Scan(), which is an
alternative to crafting a custom recursive descent parser for a particular
grammar. The tipping point depends on whether you want to read only a small
portion of a much larger document. If so, then using the ptree will likely be a
"faster to code" route. Documentation on how to navigate a ptree can be found on
the boost website and there are a number of examples in the
pcbnew/eagle_plugin.cpp file in this project. Powerful path navigation support
makes it easy to extract a subset of a ptree.

Make dialog footprint wizard list resizable.

(when disabled they are shown as standard holes, a lot less distracting
than the previous fixed yellow color)

Better description for entities on right click menu and panel
Typo fixes and some comment reformats

Charras beat me on fixing the include/sch_item_struct.h include issue from 4069

Gerbview, layer manager: add option (popup menu) to always keep layers not visible but the active layer, even when the active layer is changed.
Pcbnew: fix swig warning for operator EDA_COLOR_T::++  (changed to function EDA_COLOR_T:: NextColor)

the spurious warning about stuff that couldn't be seen when changing
colours.
NOTE that the 'net name' layer is present and configurable but non used 
anywhere!