[JDK1.6 compatibile task #695 and #676] Update Amino codebase to use JDK 1.6 APIs

[maheshrajus]

1) PR is raised for the issues #695 and #676 2) If any APIs used which are higher than JDK 1.6 version then compilation issues will be thrown 3) JAVA6_HOME need to be set if we want to compile the code with JDK1.6 ex: export JAVA6_HOME=/usr/lib/jvm/jdk1.6.X.X this we can set in gradle.properties also.

Note: Document changes we can handle in the issue: #694

Compilation Report:

Sample Error: [when we used lambda expression in Amino.Run code]

[quinton-hoole]

What is the status here @maheshrajus ? Did you discuss with @VenuReddy2103 ? Is this ready for review yet?

[VenuReddy2103]

What is the status here @maheshrajus ? Did you discuss with @VenuReddy2103 ? Is this ready for review yet?

Discussion Summary:

1. Our current gradle version(4.10) requires java 1.7 or later to be installed. It detects java version internally and throws below error if we don't have 1.7 or later version available. So we must have 1.7 or later installed.
2. Havejdk6Path property defined in properties file. This must be set with JDK 6 Path. Check and throw exceptions in following cases:
   1. if jdk6Path property is not set
   2. Or if that is set with some JDK other than 1.6. [We can extract java version with the provided jdk6Path property's bin folder, upon executing java --version internally]

NOTE: We just need JRE 1.6(actually require only rt.jar of 1.6). We don't need complete JDK 1.6 to be installed to compile source with 1.6 compatibility. Will check further on this.

[maheshrajus]

When JDK1.6 path not set:

When JDK1.8 path set:

Compilation & examples test report: