License file update
Merge branch 'hans'
sdreport: forgotten drop=FALSE
- ADREPORT failed when reporting single scalar depending on random effects.
GPL-2 in DESCRIPTION
Changes to solve most library unloading issues:

    Added script to test if reload works
    - See tmb_syntax/test_reload.R

    Fix 'failed to cleanup' problem
    - Introduced in R-3.1.0
    - Not a problem in R-3.0.2

    compile: unload dll if already loaded in order to get write permission
    - Only for windows
Update README.md

typos and notes about library re-loading
Update README.md

Notes about compiler warnings.