The reference documentation is now organized in asciidoc bookparts.
Bookparts sections can be also put in separate files, when their
size and theme are important enough to justify that.
Documentation Layout:
```
index
|-- overview
|
|-- whats-new
|
|-- core
| |-- core-beans
| |-- core-aop
|-- testing
|
|-- data-access
|
|-- web
| |-- web-mvc
| |-- web-view
|-- integration
|
|-- appendix
|-- appx-spring-tld
|-- appx-spring-form-tld
```
Supersedes and closes#641
Issue: SPR-12309
Deprecated CommonsPoolTargetSource (supporting commons pool 1.5+) in
favor of CommonsPool2TargetSource with a similar contract.
Commons Pool 2.x uses object equality while Commons Pool 1.x used
identity equality. This clearly means that Commons Pool 2 behaves
differently if several instances having the same identity according to
their `Object#equals(Object)` method are managed in the same pool. To
provide a smooth upgrade, a backward-compatible pool is created by
default; use `setUseObjectEquality(boolean)` if you need the standard
Commons Pool 2.x behavior.
Issue: SPR-12532
This commit ensures that single quotes nested in double quotes in
code examples in the reference manual are properly escaped using ''.
Issue: SPR-12246
Juergen Hoeller
Michael Simons
Stephane Nicoll
Sam Brannen
Kazuki Shimizu
Brian Clozel
Stephane Nicoll
Phillip Webb