Unlist Mismatch LDO in pcb hacks
Rename Design for Redundancy chapter
Remove schematic images
Merge pull request #63 from dmpro2014/cleanup-pcb

Cleanup pcb
Put component section last in pcb chapter
Remove troubleshooting from pcb section
Add troubleshooting to discussion instead
Remove usb schematic and add short mention of ESD
Rewrite start of 'physical implementation'
Make comments changes