Update install_erpnext.py

Update is_redhat variable becose distribution response with "red hat enterprise linux server" and response is False.
[ui cleanup] [minor]
[fix] [minor] accounts payable ageing data
[cleanup] [ui] minor
Update accounts_payable.py
update install docs
[fix] [minor] budget variance report fixed
Merge pull request #1029 from akhileshdarjee/1310

[fix] [minor] budget variance report fixed
[minor] favicon
[docs] knowledge files and faq
Merge pull request #1030 from fogueri/master

[docs] knowledge files and faq
Merge pull request #1024 from dbinary/patch-1

[minor] Update install_erpnext.py
[fix] [minor] updated message for conversion rate
[fix] [minor] conversion rate validation message update
Update sales_analytics.js

Fix a error caused after the translation.
Merge pull request #1034 from akhileshdarjee/1310

[fix] [minor] updated message for conversion rate
[docs] faq repacking
Merge pull request #1039 from fogueri/master

[docs] faq repacking
[fix] [minor] budget variance report logic + loading time
Merge pull request #1035 from MaxMorais/patch-1

[minor] by Max - fixes after translation in sales_analytics.js