Refactor dependency expansion

Change crew to hide `buildessential` from dependencies list since it is a fake package.
Change crew to not check :build dependencies if a target is already installed.
Chagen crew to remove unnecessary push_dependency call.
Change package.rb to update comments

Adding cmatrix package

Add readline dependency to R

DEBUG_SYMBOLS modification

Update openssl to 1.0.2l and distribute with pre-built arm binaries

Update mlocate homepage url

Change openssl.rb to strip binary and libraries and prepare to install man correctly.
Also add check method to check the correctness.

Correct scrollz

Update mandb to 2.7.6.1 and strip binary and libraries.

Change python27.rb to add check method and optimize for size

Modify dependencies in several packages.

Change to use tar for the performance

Remove unnecessary comments, fix quotes inside descriptions

Add package descriptions and homepages

Fix mlocate package permission issue #669

Change perl.rb to add source compile method and strip binaries