Default and most recently used path fixes. (fixes: 1494210)
* Rename Eda_FileSelector to EDA_FILE_SELECTOR. * Add optional pointer to wxString to save the most recently used path to EDA_FILE_SELECTOR. * Rename Eda_DirectorySelector to EDA_PATH_SELECTOR. * Replace wxGetCwd() with wxStandardPaths::GetDocumentsDir(). This fixes the windows issue where wxGetCwd() returns the path where the executable files are located. * Add code to handle most recently used path to EDA_BASE_FRAME. * Fix string formatting error in kicad/files-io.cpp. * Remove setting and restoring current working directory when launching GerbView. Setting the CWD has no effect on the launched executable which starts with it's own CWD. * Allow project path to be passed to GerbView when launched from KiCad. * Note: this is a work in progress. Do not expect every path and/or file selection dialog to properly update the most recently used path. The correct solution to this problem requires a much more well though out solution which will not happen until after the next stable release.