Merge pull request #115 from Arcterus/master

Fix for latest Rust
Implement tac (closes #117)
Remove a couple of programs from the to-do list
Merge pull request #118 from Arcterus/tac

Implement tac (closes #117)
tac: fix an issue with --separator
Merge pull request #119 from Arcterus/tac

tac: fix an issue with --separator
Add paste (closes #120)
paste: make MUCH faster and fix a couple bugs
Remove paste from the to-do list
Merge pull request #122 from Arcterus/paste

Implemented paste