fix #838 prefer `updateRootMap` instead of `rootFolderPath` in NodeJS

This commit adds `DownloadMgr.updateRootMap` call in the AT loader for
NodeJS, so that the user can change `Aria.rootFolderPath` to a folder
of his custom files, without worrying of breaking the loading of AT
internal files (`aria.*` classpath).

This is a backward-compatible commit, a prerequisite for #805 which will
change the default `rootFolderPath`.

Close #838.
fix #775 popup widget positioning

Allow mixing of absolute and relative positioning for popups.

If a domReference/referenceId is given and an absolutePosition configuration,
then the given absolute positions will overwrite the ones calculated based on the given reference.

Added tests for the new behavior.

Close #792
feat #797 Improvement of page definition for page engine

Two features are added with this commit:

1 - property "contents" is no longer mandatory in a page composition
2 - The bean definition for "placeholderContents" has been changed in order to reflect the code: values in the map can be either a single content or an array of them. The code was already taking that possibility into account. Tests have been added also for the case in which a template and a contentId are set in a placeholder configuration.

Close #797
fix #800 absolute path for DownloadMgr.resolveUrl

Adding the possibility to pass an absolute path to the resolveUrl method of DownloadMgr.

Close #844
doc Fix missing doc, wrong types, typos

1) make type="implements Foo" notation consistent with the other classes.
Search for `@type(.*)\.I[A-Z](.*)` in the repo, we never precede it with the Object

2) missing `$urlService` in the API docs while `$requestHandler` is there

3) typos

4) remove `@event` annotation, it's useless and not used in most of the
other files

Close #795.
refactor Cleaned up widgets by moving tagName and $cfgBean to prototype.
feat #845 Added new html textarea widget

Close #845
fix #721 changed the way comments are detected in the parser

Instead of checking that there is no ':' in front of
the occurrence of a //, it is checked that there are
some specific characters or a whitespace.
This fixes the problem with the base64 urls which may
contain // somewhere but still allows users to comment
their code.

Close #772
refactor add `.gitattributes` file

This commit adds `.gitattributes` file which tells Git how to handle
internally certain kinds of files.

It also renormalizes the repo to use the new settings (hence 3 additional
files are changed).

Thanks to this settings file, the repo will always behave in the same
predictable way regardless of the user's `core.autocrlf` settings.
I.e. hopefully we will never have "whole-file-has-changed" diffs anymore.

For more info, see:
http://stackoverflow.com/questions/170961/whats-the-best-crlf-handling-strategy-with-git
https://help.github.com/articles/dealing-with-line-endings

Close #849.
fix #771 Allow JSONSerializer to parse date values.
fix #810 Now using the robot to simulate user interaction.
fix #850 IOFilter wrongly encoded jsondata in setJsonPostData

'data=...' was also added. This hardcoded parameter has been
removed, as it should be managed by the requestHandler directly.
fix #834 Fixing autocomplete border-color

Fixing the autocomplete mandatory focused and error focused border-color properties.
fix #804 Provides detection for IE11.

Close #848
refactor CRLF

Close #851
refactor add trailing newlines

Close #851
fix #697 ESC in autocomplete resets the input to is previous value in FF

Close #809
fix #840 getStyle for backgroundPositionX/Y

backgroundPositionX and backgroundPositionY are not standard,
so these values have to be collected by parsing the backgroundPosition
value (for simple cases).
fix #747 issue with backgroundPositionX and backgroundPositionY on FF
feat #853 Addition of a test on html:Template widget

Close #853