fix(directive): fix memory leak on scope destroy
feat(select): close select box with 'esc' key
perf(options): use infinite scrolling for more than 100 options
feat(styling): make font-awesome optional via own css classes and make button texts customisable
doc(demo): improve demo with more content
chore(project): bump version to 0.3.0
docs(changelog): update changelog for 0.3.0
Merge branch 'release/0.3.0' into develop
chore(project): bump version to 0.4.0-SNAPSHOT