#75 Spelling mistakes fix

[Cœur]

In this file:
https://sourceforge.net/p/squirrel-sql/code/HEAD/tree/trunk/sql12/fw/src/main/resources/net/sourceforge/squirrel_sql/fw/util/I18NStrings.properties

You can fix the following three spelling issues:

- MyURLClassLoader.errorLoadingClass=Error occured trying to load class {0}
+ MyURLClassLoader.errorLoadingClass=Error occurred trying to load class {0}

- MyURLClassLoader.errorLoadingFile=Error occured trying to load file {0}
+ MyURLClassLoader.errorLoadingFile=Error occurred trying to load file {0}

- TaskThreadPool.errorDuringTaskExecMsg=Error ocured during task execution:
+ TaskThreadPool.errorDuringTaskExecMsg=Error occurred during task execution:

[Gerd Wagner]

Closed according to feature request #516