Upgrade to Spring Boot 1.0.0.RC5

Includes refactoring to changes made in spring-projects/spring-boot#467
Prune duplicate static resources
Merge pull request #309 from spring-io/upgrade-boot-rc5

Upgrade to Spring Boot 1.0.0.RC5
Add license and copyright information
Remove trailing whitespace
Refer explicitly to "sagan" as the project name
Eliminate "1.0.0 GA" version number
Update Boot version from 0.5.0.M7 => 1.0.0.RC5
Prune libs static resources as well
Merge pull request #312 from spring-io/prune-static-resources

Further prune sagan-site/src/main/resources/static
Merge pull request #122 from spring-io/license

Publish license details
declare inputs+outputs for npmBuild gradle task

This commit adds inputs/outputs to the npmBuild task in order to speed
up the Gradle build and skip this (time-consuming) step of the build
when it's already up-to-date.
Merge pull request #307 from spring-io/sagan-307

Merge additional changes in #307 - the npmBuild task should also
declare Gradle inputs/outputs to speed up the build.
Fix warnings as reported by STS
Fix missing CSS file from blog

The gulp build now processes all CSS files.
Improve error message for search errors

When running the Sagan app for the first time, the app is probably
not configured to use an existing ElasticSearch index. So the search
feature doesn't work properly.

This commit adds a specific error page that points to Sagan wiki pages,
thus providing insight on how to properly use an ElasticSearch instance
with the Sagan app.
Log npm downloads at Gradle's LIFECYLE level
Merge pull request #313 from spring-io/sagan-313

Improve error page when search not enabled
Apply responsive.css and tools.css changes

Visually verified the changes appear to
match https://www.pivotaltracker.com/s/projects/811409/stories/55775424

Original changes made by @jacksoncvm
Merge pull request #85 from jacksoncvm/55775424-new-noteworthy

Update tools page with New & Noteworthy box