Introduce `StringIO.flush/1` function
Support mix help --search PATTERN
No longer inline binary expressions in EEx

String.Chars is now always inlined by the compiler.

Closes #2815
fix typo
Merge pull request #2816 from jw2013/typo

fix typos
Fix missing concatenation operator.
Fix test for mix deps.clean.
Merge pull request #2819 from benjamintanweihao/patch-3

Fix missing concatenation operator.
set null prompt function in dumbterm mode
Merge pull request #2821 from k1complete/shown_prompt_erlsh_in_dumbterm

set null prompt function in dumb term mode
Do not set not shell as we know have a custom prompt
Merge pull request #2807 from pma/support_mix_help_search

Support mix help --search PATTERN
Merge pull request #2793 from lexmag/master

Introduce `StringIO.flush/1` function
Update CHANGELOG
fix typos
Merge pull request #2822 from pooya/avoid_an_before_s

fix typos
Fix typo
Merge pull request #2824 from benjamintanweihao/patch-5

Fix typo
Use unamed tables for module compilation

* We have created a main named table that keeps all module information

* We have reduced the amount of tables by storing internal, docs and
  attributes altogether and using table looks for retriving the relevant
  information

* At this moment, creating a module in Elixir defines three tables,
  one for data, another for functions and another for clauses
correct is_nil @doc to have the same format as the other is_* functions. So it is consistent in the Kernel > Summary docs