PMD is currently not working properly for Java classes that use [unnamed
packages](https://docs.oracle.com/javase/specs/jls/se11/html/jls-7.html#jls-7.4.2).
Consider the following Java class that does not contain a `package`
declaration:
```java
public class App {
String getGreeting() {
return "Hello world.";
}
static void main(String... args) {
System.out.println(new App().getGreeting());
}
}
```
Running PMD in the command line agaist the Java class above produces an
output with empty string `""` in the `"Package"` column:
```sh
$ pmd -R category/java/bestpractices.xml -f csv -d './src/main/java/App.java'
Oct 02, 2018 9:10:39 PM net.sourceforge.pmd.PMD processFiles
WARNING: This analysis could be faster, please consider using Incremental Analysis: https://pmd.github.io/pmd-6.7.0/pmd_userdocs_incremental_analysis.html
"Problem","Package","File","Priority","Line","Description","Rule set","Rule"
"1","","/Users/diego/Projects/github.com/dlresende/kata-fizz-buzz/src/main/java/App.java","2","7","System.out.println is used","Best Practices","SystemPrintln"
```
But the pmd.vim handler's current pattern refuses everything coming
from a Java class that does not have a package name (2nd column):
```vim
let l:pattern = '"\(\d\+\)",".\+","\(.\+\)","\(\d\+\)","\(\d\+\)","\(.\+\)","\(.\+\)","\(.\+\)"$'
```
The solution I am proposing is to also accept empty strings as package names.
* The project style linter now runs while you type.
* Now the scripts for checking the project require blank lines.
* Many style issues have been found and fixed.
* Remove 'col' from linters where it is hardcoded to 1
When 'col' is 1, the first column will get highlighted for no reason. It
should be 0 (which is the default).
In the scalac linter there was also a check about the outcome of
`stridx`. It would set l:col to 0 if it was -1, and then it uses
`'col': l:col + 1` to convert the outcome of `stridx` to the actual
column number. This will make 'col' equals 1 when there is no match. We
can remove the check because `-1 + 1 = 0`.
* Remove outdated comments about vcol
vcol was added as a default, and the loclists that follow these comments
do not contain 'vcol' anymore
* A try at javac support for ALE
* Small cleanup: moved '/tmp/java_ale' string into script var
* Fixed Travis-CI build failing on autocmd not being in augroup and stupid omission
* One more fix for Travis-CI
* For some reason, expandtab was not set
* Indentation and removal of header guard.
Used examples from ale_linters/c/gcc.vim and
ale_linters/javascript/eslint.vim for the indentation of string concat blocks.
