Adds symlink to File

implementation of feature request #2114
Use Application.format_reason when formatting application exits
Print all errors in case of missing files, closes #2239
Fix mix test
Only print char lists if in the ascii range
Do not throw/catch, instead use Process.info/2
Compiler now mentions which file has a duplicated module. Fixes #2131
Fix two test cases
Fix compile error during boostraping
Removed superfluous 'be'
Merge pull request #2241 from stoft/master

Grammar, removed superfluous 'be'
Merge pull request #2240 from gmcabrita/fix-duplicated-module

Improve compiler message when duplicated modules are detected
Hide module's location attribute
Create remote funs even in &mod.fun/arity, closes #2133
Merge pull request #2123 from duksis/symlink_on_file

Adds symlink to File
Rename symlink to ln_s according to File's convention
Use rebar hosted on S3
Ensure aliases are respected on root, closes #2227
Improve docs for generated apps
Improve application error formatting

* Format (nested) supervision tree init failures
* Format :gen_server exit reasons
* Fixes :invalid_options text
* Fixes text when when application start returns {:error, reason}