[pl] Verify and synchronize Polish content

[crabonature]

• Downloads - --> Community/Ruby-core/
• Documentation
• Documentation/Ruby from other languages --> links to not translated articles
• Documentation/Ruby from other languages/To Ruby From C and C++
• Documentation/Ruby from other languages/To Ruby From Java
• Documentation/Ruby from other languages/To Ruby From Perl
• Documentation/Ruby from other languages/To Ruby From PHP
• Documentation/Ruby from other languages/To Ruby From Python
• Documentation/Success stories
• Documentation/Quickstart
• Installation
• Libraries
• Community
• Community/Mailing lists
• Community/Conferences
• Community/User groups
• Community/Weblogs
• Community/Ruby-core/
• Security
• About Ruby
• Home Page

[crabonature]

libraries - 0d557d4
home - 82c236c
documentation - e6d7914
security - 668988c
footer - bef0a29
downloads - 5dc4487
about, community - a97686d

[crabonature]

Ruby from other languages - 6851787
To Ruby From Java - 31116b6
To Ruby From PHP - 6c986d1
To Ruby From Python - 7e41f2a
Installation - 3cba171