Autoinjectors

*Adds 4 new autoinjector items: Bicaridine, Kelotane, Antitoxin(Dylovene)and Dexalin, each with their own sprite including inhands!

*Autoinjectors hold 8u of a medicine and inject 4u per use but are impossible to refill.
*Replaced all kelotane pills in the burn kit with kelotane injectors.
*Replaced two dexalin pills in the o2 kit with dexalin injectors.
*Replaced all antitoxin syringes in the antitox kit with antitox injectors.
*Added 5 autoinjectors of every kind to the medivend.
*Also added 5 syringes filled with kelotane and bicaridine each to the medivend to encourage doctors to pick their medical supplies according to their needs.

![medipens](https://cloud.githubusercontent.com/assets/7812993/3507672/49511402-0681-11e4-8ebe-475ef60e8abb.PNG) (slightly outdated, the injectors now have a little needle visible, the black injector is unused)

...also my first pull request, let's hope I didn't mess this up!