Merge pull request #1 from KiCad/master

update
fixed broken links to 3d models
fixed broken links to 3d models - 2 more
removed 2 bad 3d
removed wings backup files
Power symbol adjusted to meet more conventional style
Fixed power symbols
.gitignore added
Removed .bak .bck files
Unified power symobls length
GND symbols enlarged
Add LM35 analog temperature sensor
Split BC516 and BC517. They are different items and BC516 is PNP not NPN
Add photoresistor
Adjust LM35 to 100mil grid
Rename Photoresistor to Photores to avoid name clash
Flip BC516 to keep collector up emitter bottom convention
Fixed GND symbols names
Removed badly named symbols
Added more negative symbols