Add csrf_token() to Jinja2 globals

Installing csrf_token() in the render context only causes errors in
imported Jinja2 templates. It can be avoided by explicitly importing
templates with context, but it is a cognitive burden to remember which
templates should be imported with context and which don't have to be.
Version bump 0.9.5
Lowercase for filename
Merge pull request #120 from seedofjoy/patch-1

Version bump 0.9.5
Remove outdated mirrors section and update broken pip v easy_install link
Merge pull request #122 from sloria/doc-fix

Remove outdated mirrors section and update broken pip v easy_install link
Fix csrf validation without time limit (time_limit=False)

With time_limit=False, generate_csrf will generate a token with an empty
'expires' value. The validate_csrf function will always fail because it
tries to parse an empty string as float. We should parse this value only
if we care about the time_limit.
Merge pull request #129 from BenoitZugmeyer/non-expiring-csrf

Fix csrf validation without time limit (time_limit=False)
It's time to support wtforms 2.0

https://github.com/lepture/flask-wtf/issues/94
Get default time limit from configuration for Form.

Related issue: https://github.com/lepture/flask-wtf/issues/131
Travis for WTForms 2.0.1
Avoid timing attack on csrf validation with `hmac.compare_digest`.
This method is only available since CPython 2.7.7 and 3.3.

Related issue: https://github.com/lepture/flask-wtf/issues/130
csrf exempt supports Flask Blueprint now.

Related issue: https://github.com/lepture/flask-wtf/issues/111
Test cases on exempt blueprint
Merge #118 Add csrf_token() to Jinja2 globals
Documentation. Prepare for 0.10
change ValidationError to StopValidation in FileAllowed filter
add default message so that StopValidation behaves properly
Merge pull request #132 from eriktaubeneck/file-allowed-stop-validation

File allowed stop validation
Use `werkzeug.security.safe_str_cmp` instead of `hmac.compare_digest`.

https://github.com/lepture/flask-wtf/issues/135