* Continue component library class clean up and encapsulation work.
* Change hierarchical sheet label container to boost::vector_ptr.
* Encapsulate hierarchical label handling in hierarchical sheet class.
* Convert some missed occurrences of wxString::GetData() to GetChars( wxString ).
* Fix some minor code formatting issues.
In netlist generation, changed the rule to calculate netnames of nets with labels:
Previously, named nets (i.e. nets with local, hierarchical or global labels) have their name
defined by the first label found in list.
So net names could be changed without really changing the schematic.
Now the names are calculated from the rules (by priority order) :
1 - use the most top level labels in hierarchies.
2 - use global labels first, local labels next (hidden power pins names are global labels).
3 - use alphabetic sort (so, if GND and AGND are connected, the net will be always named AGND,
and adding a VSS connection cannot change the net name)
So power nets and nets that have more than one label cannot have their netname changed
if there is no actual change relative to these nets names in schematic
* Complete comment translation for all EESchema source files.
* Complete comment translation for all 3D viewer source files.
* Rename class class_hierarchical_PIN_sheet to SCH_SHEET_PIN.
* Rename class DrawSheetStruct to SCH_SHEET.
* Tool tip capitalization fixes.
* Uncrustify and spell check comments and strings in all modified source
files.