Added Ubuntu requirements to README.txt

Signed-off-by: Rafał Malinowski <rafal.malinowski@corp.bluecherry.net>
Added missing include for some systems

This include is required on older Ubuntu for execv function.

Signed-off-by: Rafał Malinowski <rafal.malinowski@corp.bluecherry.net>
Merge pull request #77 from vogel/ubuntu-build

Ubuntu build
git: Ignore files resulting from build
Merge pull request #79 from ismaell/gitignore-build

git: Ignore files resulting from build